I have been a technician for 14 years, but the way Jason explains things, is second to none. I honestly do not know of anybody else that can do it as well as he does.
Lugging is a long-held tradition for high-efficiency cruising in aircraft and cars, although it's not as useful for cars since we do most cruising at high speed without tall enough gearing. Inner-cyinder temps and times leading to pre-ignition? You can hear and feel that. Longer-term temperature increase? There's a gauge for that. Obviously if you are making a pass, you don't want to lug, but for a completely different reason than the video states: you want to pass quickly! I will happily continue ignoring the (bad and amateurish)advice given in this video. Negged!
@@JENKEM1000 it's not bad advice at all - giving a vehicle wide open throttle at low rpms (e.g. when you're barrelling down a highway) is bad, light pedal pressure is ok. Engine lugging is the former, not the latter. If you need to overtake at highway speeds and your engine is at low revs with more than 50% throttle that's going to create problems if you keep doing it, downshift instead.
Hi EE, great presentation on a topic that is so much misunderstood. I did my engineering 35+ years before you and had the same conclusion but without the use of turbo, and the studies of Toyota and the computerized simulations that can be done nowadays. We (Ford) tested shock waves propagation on the rotating assembly, engine block, drive train (flywheel and damper), in a low rpm, high and low load, and high mixture (those were the sensors we had back then). We looked at the effect of lugging the engine and also at revving the engine under no load (like "kids and motorcyclists enjoy doing at red lights" and reported much greater stress on the engine components than at high rpm. The test scenarios eliminated air/fuel ratio imbalance, detonation, pre-ignition, as far as the technology of the day allowed. We also used engines that were "mint", all parts polished and cleaned for any debris, assembled to specifications by top technicians and engineers (truly yours included), optimal cam profile and ignition timing and test calculations with the best gear of that era. The consensus was like you mentioned plus we noticed extra vibrations, increased stresses on all parts, would decrease the life-cycle expectancy of most of the moving components of the engine/dyno linkage. We concluded that the engine (Ford 335 engine family) could take it, under the best conditions but the ultimate life of the engine/drive-train would be adversely affected. Did your studies looked at stresses on engine components aside without LSPI? Thank you - Ciao L
This explains two things: - why I fouled the plug in our lawnmower (yanking the safety off and on at low revs is probably like "lugging" it), and - why I'm hearing about fuel dilution in the oil in newer small-displacement turbo engines. Nice use of ten minutes. Keep it up.
Really great to hear a thorough explanation of this and the science behind it. People thought I was crazy and trying to cause hysteria in EcoBoost owners when I talked about the dangers of LSPI in the EcoBoost Mustang. Some of the guys on the EcoBoost Mustang forums have also seen some correlation between LSPI and high calcium content in oils and the higher volatility of some oils. It seems like lower calcium content is safer for the EcoBoosts. The safer path for paranoid people like myself: don't void your warranty and/or get something naturally aspirated instead lol.
LSPI can pretty much happen in any car, it's just that it's more common in newer turbo engines because they use DI, which means higher compression ratios, and they generally use small turbos which spool much quicker, which means a lot of boost at low RPMs. LSPI is not just an ecostang or ecoboost issue, it applies to the new WRX, VWs, etc. I wouldn't even necessarily even call it an issue, it pretty much only occurs when you're doing something wrong. There can be flukes, but generally it's a driver issue, not something wrong with the car. You didn't really see LSPI in old turbo engines because the compression ratios were lower and the turbos didn't really spool until like 4-5k+ rpm. You could still have LSPI happen in NA, it's just not as likely. Lugging an NA engine is still horrible for it. One of the issues is that turbos or big engines produce a lot of torque and that can mask the fact that you are lugging your engine. (because they accelerate fairly well) Obviously though, it's going to be much easier to lug an NA 4 cylinder vs a V8. (within reason) Not trying to lecture you, just clarifying. :) EE feel free to correct me if I'm wrong. You'd know more than me. lol
connecting rod loading is pretty much what pre ignition/ knocking does in your motor. the combustion will be happening before top dead center on the ignition stroke and the flame from the ignition will meet the top of the piston before the piston is at top dead center and tries to force the piston back down as the piston is coming up to ignite when its supposed too, so its pushing back on the piston connecting rod which can nend connecting rods or even worse blow the piston out the bottom or side of the motor blowing the engine up :P but hopefully your engine will never knock that bad because the knock sensor can sense pre ignition before you can even hear the engine starting to knock and pull timing as needed
+CSmittyBurz This makes sense. I've never heard of this issue with the 3000gt VR4 guys. I've chugged along the "grape vine" in California plenty of times in a high gear at a low RPM with ~1-2lb of boost or so with no knock detected in my VR4. It must be because of the low compression and no DI.
Absolutely love your explanations Jason. You cover everything quickly and efficiently and even throw some tips at the end, and it boggles my mind how you do all your videos in one take.
I've been a diesel technician for six years. Their are tests from the vehicle manufacturers that tell you to do a lug down in order to simulate a fully loaded trailer. When you do a lug down if you have a plugged doc or dpf, failing turbo or turbo waste gate, or failed egr valve or thermalanagement valve this test will let you check readings for boost and intake manifold pressures. If the vehicle hits a certain rpm and doesn't start acceleration under boost then you can identify the problem. So while it may not be good to do all the time there is still tests that require you to do a lug down Still awesome video and explanations
Depends . Diesels don’t rev high to begin with, and they make all their torque in the low rev range which is a lot of torque dude to the long stroke. You can’t really lug a diesel. A gasoline engine with a turbo depending the size of the turbo there isn’t much torque down low due to a shorter stroke to be able to rev higher and make more horsepower. This is where issues occur
I enjoy watching many of your videos, but as an engine engineer, there are a few points I would like to comment on that are not very accurate in this video. Regarding engine being less efficient when lugging, it is not completely accurate. First of all, it depends on if you are talking about overall efficiency or combustion efficiency. Regarding combustion efficiency, it is a balance between heat transfer loss (which is more prominent at lower RPM) and friction loss (which is more prominent at higher RPM), so the sweet spot is engine dependent (over-square vs under-square, how the wastegate/bypass logic works etc.), somewhere is the middle of the RPM range. But overall efficiency, which includes pumping loss, will tend to be higher at lower RPM since there is less pumping loss at lower RPM to achieve the same brake mean effective pressure (BMEP). So it is all relative depending on how low of an RPM you call it lugging the engine. The second point is that on your graph you have the spark timing after TDC, which is not very accurate. Most modern cars have the ignition timing before TDC, since SI engines have ignition delay, i.e. the charge does not immediately ignite after spark. One last point is that you did not point it out explicitly, but this explanation is for SI engines. CI engines (diesel for example) has a different mechanism and there are a few points you pointed out here that would not apply to CI engines. Also, there are many comments from the viewers that said the ECM could take care of it. I think it is good to clarify that unlike knock, pre-ignition is not as easy to handle as knock in an engine. The main logic to move away from knock is by retarding spark timing. but since pre-ignition is not triggered by the spark from the spark plug, it is fairly challenging for the ECM to handle it. Good luck with your channel and the future videos.
Si stands for Spart Ignition engines that so require a spark to ignite air/fuel mixture - gaz(propane, CNG, LPG), gasoline, ethanol (E85), engines Ci stands for compression ignition, let’s say Diesel engines Cheers
Great precisions, right. Concerning the TDC related spark advance I think Jason means the moment of combustion accuring so it’s simpler to explain without the firing delay...
Your insights are pretty much what I was thinking, too. I know that overall efficiency is usually higher when the engine is at lower RPMs and higher loads, which is what I usually try to do when I'm driving (sometimes more "aggessively" than I should, if you can call "accelerating as slowly as possible without stalling" aggressive). I'm now puzzled with this situation, how can I take advantage of the low RPM high load efficiency boost while still making sure I'm not damaging my engine by lugging it? Any insights?
I always wonder if I'm lugging the engine on my diesel Volvo. The gearbox upshifts very early and even under medium acceleration at ~1200rpm, it doesn't downshift unless I jerk the accelerator to force it to. The engine's audibly humming louder and there's a bit of vibration. Is this bad?
+Oscar Lee If your car is shifting early I font think that's exceptionally bad? But it is odd. The audible noise is definitely not good. Go post and look on some forums before you ho spend any money at the mechanics. Or call Car Talk on NPR.
The noise can be described as a hollow sound that my other diesel car also makes when at low rpm, and a bit of load. I wouldn't worry about spending money on it since it's still under warranty.
So my last car was a Mazda CX-7 with the MZR2 Turbo. The Transmission on this vehicle would allow you to manually shift and you could go with WOT at very low RPM in higher gears. Being it was a single scroll turbo there was lag but it would pull pretty hard in the higher gears. It also produced a ton of smoke. Eventually the seal on the turbo blew. The engine later started having serious issues stalling and misfiring while dumping smoke out the exhaust. I did not have much done to it as I was looking for a new car and did not want to dump a ton of money into it. I was told the very thing that damaged the engine and the seal on the turbo was WOT at low RPM under load. The car I have now is also a turbo 4 but it will not allow you do this. If you floor the pedal at low RPM the transmission down shifts , even in sport mode. So I learned about this the hard way. Mechanic said, would you start from a dead stop in 4th gear?
I always wondered what happens when accelerating too fast in low RPMs. But you can hear the engine straining and it's common sense to avoid that situation.
Very good information. People have always told me that lugging my engine is damaging, and of course, there are very obvious reasons why it wouldn't be in my best interest to do so. However, I've never really believed any information I've read on car forums simply because nobody could back up their claims concerning the damages and risks involved in doing so. I've looked into the study done by Denzo and Toyota, and now I understand why this is bad. Keep up the great work Jason. I learn a lot here. I've also picked up that book you recommended--Physics for Gearheads. My degree is in Physics, and my main struggle has been explaining in layman terms the physics of performance vehicles when my friends ask me various questions. Mainly because I like math too much. This has been a great resource in order for me to refine my language when explaining these concepts, and learn some new information myself. Keep up the great work! I may have an unpopular opinion here, but I'd like to see some more math!
Hey man, algrebra is tricky. I did well in Algebra I, Algebra II, and geometry, but once trig and calculus came along applying everything I learned in all of these classes was tough. It takes a lot of patience and practice, but once you get it, it's great fun. It's like solving a big puzzle.
Not always the best policy. Drive in the engines optimum power band is the best in experience. Low revs doesn't necessarily benefit economy either. You need airflow to achieve good air:fuel mixing. This doesn't happen optimally at extremely low revs.
paulanderson79 true... Efficiency is the key to economy AND power. Too low of rpm and you are wasting fuel due to not enough air flow to burn it all. Too high of rpm and you are now ignoring the efficiency peak and going for peak power. The very start of your peak torque curve will be the most fuel efficient for your car. Mine is from 3-4k (out of a 9.3k redline) below that and my torque band is very low, above that and my variable vavles begin opening to optimize performance and the car start to get richer AFR to make the most power rather than Torque
How about diesel engines? Diesel cannot ignite the fuel too early because the fuel is not injected until the moment it's supposed to be burned. Of course, if you lug the engine low enough to cause vibrations higher flywheel (or dual mass flywheel) can take, you will cause huge stress to transmission. However, do you have a reason to state that the engine itself would be damaged by lugging the diesel engine? (Let's assume that we're speaking about direct injection turbo diesel engines here...)
The fact turbocharged engines are becoming very commonplace & many of them advertise their dynos with very beefy low end torque numbers. This probably gives the wrong impression that manual drivers won't need to downshift to pick up speed, hence the lugging.
2015 WRX here. If I'm traveling in top gear cruising on highway and want to floor it then I always downshift accordingly and then do upshifts all depending on what speed I am doing. Otherwise it will bog down. This is my first turbo and love it. This is me coming from my first car 1995 Ford Escort LX wagon then 2001 Civic. Both were 5-speed manuals but of course they had very low HP. Day and night difference with current car lol.
Yeah. You can have maximum torque and still be able to lug the engine. My daily driver is a small turbo diesel and while it has a ton of torque starting at 1200rpm it actually has very little power in that range. Means I can hold a speed at incredibly low rpm but if I need to accelerate - to the lower gear it is. I think the operative definition of lugging is to ask the engine for more power than it can deliver. You can have all the torque you want but if you try to exceed the power rating at a particular rpm you're essentially feeding the engine too much fuel. I guess people cannot grasp this "discrepancy" that you can have loads of torque but no power and think that they get more torque by pushing the pedal.
You've made a car guy out of me...I'm pretty sure everyone that knows me is probably sick of hearing me talk about it by now, so thank you! :) ...also, as a new owner of a manual transmission vehicle, and it being the only stick I've ever driven (people don't own them these days, I had no other way to learn!) ...these videos have been ESSENTIAL to my driving...so, my engine and transmission thank you too!
If things like pre-ignition don't apply to diesel engines (which only take in air rather than airfuel mix) you should state this clearly in your video please. Here in Europe we use Diesel a lot.
Good really in depth video of things that go wrong that the average driver will not be aware of. I believe that lugging does not only happen at full throttle as mentioned a few times but is generally what happens when you try to accelerate in too high a gear for your current speed. The engine may vibrate and could even cut off if extreme. Another negative effect of Lugging that I did not hear you mentioned is low oil pressure due to low engine speed. Low oil pressure can lead to increased wear on bearings and to have low oil pressure at a time when you are placing greater load cannot be a great idea. Additionally I have heard that it is well known in the automotive world that the ideal oil pressure is somewhat above what would trigger your oil light so when you get to the oil light stage things are worse than you might think. Of course there is material to wear and it is not an instant disaster but one that can be avoided by always being in the best gear which is why we drive a manual in the first place. Lazy shifters should switch to an auto. A true manual driver gets a thrill out of being in the best gear for the moment and beyond the moment by being proactive as the next gear is anticipated. This level of driving can only be achieved in an auto by connecting it to cameras and gps or the brain of the driver. Autos will always be reaction based compared to manual.
A good example of this is with diesel engines. car engines rarely run at full loads but diesels often do. A diesel in a semi truck or heavy equipment will run at full load for hours at a time. If you have a pyrometer you can watch the exhaust temp climb as the rpm falls below the power band. Soon after, if you continue lugging the motor, the fuel temp will climb on motors that have an internal fuel rail and coolant temps will climb. On tier 3's exhaust sooting will occur and cause Regen cycles. Eventually the ECU will fault for one of these. A teir3 Caterpillar held at 1600 under full throttle for an hour will fault. Try it with a gas motor in a car.
basically it's OK to rev a petol engine higher, but you DON'T need to do this with a diesel engine, since the fuel is sprayed into the cylinders after peak compression and immediatly ignites. So my fellow Europeans, don't worry, you've not been taught wrong if you drive your diesel engines at low RPM, you're helping the environment ;)
I was about to ask that, because most large diesel engines are really slow, trucks are best at 1-1.5krpm, tractors aren't known for revving high as well. I think he really should've specified what engines this applies to.
@@kristapsjj8520 i have a range rover evoque which has a 2 litre diesel engine (163'500km). when i drove around 52km/h the engine rpm were at around 1.2k, it started to make a vibrating sound. over 1400rpm this didn't happen. Today I did some pulls on full throttle, which the car basically never experienced in its lifetime, and the vibrating noise was gone when the car was operating on such low rpm
@@c190gtc I can only speak for my engine. The D5 is notorious for soot. After driving for 500km as a grandma it's good to rev it once in a while and get all of that crud out of the exhaust etc.
When I was allot younger I would do this with one of my big single cylinder motorbikes as it would make an awesome groundshaking thumping sound when in 5th gear and at low speed with the throttle wide open. When I came to do the first oil change there were shards of metal in the filter and sump. Lesson learnt.
Sounds more like a fucked up tranny (pun partially intended). It's amazing how randomly people link incidents and causes. If you rev your vehicle into the limiter directly after a cold start, and then a minute later your headlight fails, do you really think that's cause and effect?
At low rpm under heavy load, the velocity of the intake charge is quite slow. The intake charge helps cool the valves and if the engine is kept under a heavy load at low rpm, this could raise the combustion chamber temperature leading to pre ignition. Think of this another way: Engine manifold vacuum. When the intake manifold vacuum diminishes (heads towards zero) the incoming velocity is also substantially reduced. Keep manifold vacuum high and the engine is happy. There was a time when some cars actually had as a factory option a so called economy (vacuum) gauge. Keeping the vacuum high resulted in the best fuel economy. A boost gauge will show vacuum and boost, it is easy to tell why you don't have boost when you have wide open throttle at low rpm. The turbocharger requires reasonable pressure of exhaust to spin up, without this your stuck in the land of diminished intake manifold vacuum. Some standby generator sets are run so hard that the valves will burn in as few as 100 operating hours. This type of load is akin to continuously driving up hill, towing a trailer at wide open throttle. This is another reason vehicles have transmissions. Let engines rev but always leave some throttle in reserve, if one must hold the throttle wide open then you are in to high of a gear. It really is about load management, and to some extent why vehicles have automatic transmissions ;>)
I've known some people to do this deliberately because they think higher gear = lower engine RPM = lower fuel consumption = better economy. I can't stand it as you can feel the engine labouring rather than pulling strong, it's inefficient and I'm confident there's no economical benefit. But I could be wrong. It could be great if you could look into this perspective of "lugging" an engine as well.
The rest of the story is that the Toyota Denso research (which all major automobile manufacturers either had access to or conducted themselves) was aimed at developing timing/fuel/air mappings that can mitigate and/or outright avoid the heat/pressure conditions resulting from lugging. If you drive a late model car with a small-displacement, turbocharged engine the computer simply won't allow you to cause damage to the engine by simply opening the throttle under any combination of throttle position/RPM. Bottom line: If you drive a race car and/or a car with custom computer tuning there are rare conditions under which you might cause damage and/or excessive wear to your engine by lugging it. And if you're driving such a car you probably already know this. For everyone else, don't worry about it, the computer won't allow you to damage your engine by stepping hard on the gas in at low speed in a high gear.
I drive a 2016 Ford Mustang Ecoboost. It is 2.3L direct injected, turbo charged. NOT with port injection also. It has blown up twice in 96,000 miles. WITH a catch can. LSPI was probably the ultimate cause, but as the ECU brings the engine to a knock then retards timing, its knocking all the time. Since the DISI engines do not scrub deposits on the valves with gasoline going over them, you have a great source for hot spots in the cylinder.
@@Orcinus1967 If there were a widespread problem with stock engines blowing up we would know about it. There are literally millions of these engines in operation around the world. Almost all of the catastrophic failures I've read about involve modified software.
@@mwsletten In my case, a 2016 EB Mustang, I purposefully did not "tune" my car using modified software. I had a 100,000 mile CPO warranty to protect. I have found much evidence of the engine having problems, especially with cylinder # 3. Chevy, Ford, major manufacturers, all do not have a problem with 2-3% of their engines being bad. It is an acceptable level, and for the most part, they fix stuff under warranty, as they have fixed mine. Twice. I re-upped and got another 43,000 miles on an extended warranty, to 2024 or 143,000 miles. I am now at 97,000 miles. 2% of 1 million engines is 20,000. Ford does not want to discuss what is wrong with the 2.3L EB. I have to draw out of my service department what failed on my car, and then its never exactly what went wrong. "The heads", for example. When you say "engines" it helps to be specific. It is not the same as other EB engines. Most people aren't on forums about specific engines. And when they are I always find misinformation from supposed experts, and folks who haven't even owned a Ford of any sort, for 20 years. Of course the average person may not have an interest in cars. So even if they did have a problem, you would never hear about it, especially if they were provided a loaner car and it was fixed under warranty. Which 2.3L Ford do you drive BTW?
@@Orcinus1967 said: "I have found much evidence of the engine having problems, especially with cylinder # 3. Chevy, Ford, major manufacturers, all do not have a problem with 2-3% of their engines being bad." Sorry to hear about the issues you've had with your car. I don't believe your experience is common. Ford just chose the 2.3L EcoBoost for use in the Ranger and the new Bronco, two vehicles Ford expects to sell very well. That's a helluva a vote of confidence in an engine. Seems crazy Ford would do that with an engine it doesn't believe is rock solid. It also seems crazy there are no stories in the press about customer complaints regarding the 2.3L EcoBoost. Ford just took a major financial hit on DCTs in its Focus and Fiesta model cars. The motoring press was all over the story as soon as customers started complaining, way back in 2011 when the DCT was first introduced. Where are the press reports about problems with the 2.3L EcoBoost, an engine that's been in service since 2015? Here are a couple of questions: 1. What is the actual failure rate of the (unmodified) 2.3L EcoBoost engine? 2. What is the failure rate industry-wide for small displacement turbocharged engines from all manufacturers? That's the data you need to determine reliability of the 2.3L EcoBoost engine. I can tell you that Consumer Reports rates reliability of Ford's 2.3L EcoBoost as above average. That's based on actual customer surveys. I have Mustang EcoBoost. No significant engine problems after 40K. The only issue so far was a small oil leak around the valve cover which was repaired under warranty.
@@mwsletten I agree with you that if it was a major problem it would make the headlines, somewhere. If not NHTSA. But there are a lot sexier narratives running these days. Those being cops shooting blacks, and covid. These engines do blow up, and, like you said, especially if you take the safety stops off, as with an after market tune, or if you decide to pump up the horses with bigger intakes and turbos etc, but not the internals by putting in better pistons and connecting rods etc. What I have been told by 1 mechanic outside of Ford is that some companies have backed out of direct injection, the technology just not being up to the task, yet. Hopefully Ford has gained experience from the engines that have blown up, and fixed any issues. Today they make the Hi Performance 2.3L. They took some safety stops off there. Changed the revs and the horsepower. They must have learned something. Years ago, 2018? I had asked a guy at Mountune (Mountune are a race engine and road-car performance specialist who alongside Ford have developed critically acclaimed packages that boost not only output but also performance.) if they could work on my 2.3 Mustang engine. They were advertising they would work on it at the time, online. When I called on the phone, however, the answer was "NO". Only the Ford Focus ST and RS and Fiesta ST. They would not say why they would not work on the Mustang 2.3L engine. Most likely they did not want to jeopardize their relationship with Ford. To me, from my personal experience, at Ford dealers and at my personal mechanic (recommended by a Ford parts salesperson) that says "there is an issue, and we are not discussing it due to the legal and cost ramifications of a potential recall". And, another thing I've heard over and over is "I have a relationship with Ford, I'm not going to jeopardize that relationship", even if it's only someone selling me a set of hood stripes in a color Ford does not want me to put on my car. I am more skeptical than you. Ugh. I'm going to clean my catch can. Cheers and good luck with your EB! I love my car and I'm keeping it til I find a V8 Stang with Magneride, used. Then I can deal with the ticking engine thing on the 5.0!
Lugging the engine usually only occurs at VERY low engine rpm, like below 1,000 or if your in 5th gear going 40mph (5spd). If when you floor it it doesn't sound like it's about to stall your fine.
Just watch the video but in summary it increases engine temp and can cause blowbly and all sorts of bad sheninigans. And it might use more fue because the engine is not efficient while lugging.
All modern turbo engines has full torque in 1300-1500 rpm (in fact 2000rpm) so all you need to do is set Sport mode in tranny and it will keep it over 2000rpm. In manual yes it can damage engine in some way.
My car hits peak torque around 5000RPM, and I would consider the 4B11 a "modern turbo engine." It cold idles around 1500, so I'm not sure where you got that statement of yours.
Why do you say that the efficiency is lower when the engine has to work hard? You are the first person I ever heard saying such a thing. According to my professors and a book "Introduction to Internal Combustion Engines" by Richard Stone among other sources, every engine is more efficient under full load than it is under part-load. I.e. if the engine has to work harder - it is working more efficiently. This is especially true with traditional petrol engines with a throttle valve. Which brings me to my next question. Does this lugging problem also affect direct injection diesel engines? You never seem to take diesels into account when talking about such matters.
I believe this is particularly true for gasoline/petrol engines thanks to the throttle, as you noted -- at part load the restriction and pumping losses reduce efficiency. At (nearly) full load, this problem goes away. At *full* load however, your engine management might make the mixture richer for that last bit of extra power, reducing efficiency again. That's not the whole story though -- it's more of a 2-dimensional problem. So, for a given RPM, you do get more efficiency with more throttle. BUT, for a given throttle position, you'll get varying efficiency with engine RPM. Apparently, the best efficiency may be around peak torque. There are probably instances where you'd be better off at 75% throttle and the "right" RPM than 90% throttle at a very low speed. I guess a given engine will have an efficiency map as a function of throttle and RPM. Things to think about would be intake tuning and exhaust scavenging, valve clearances and swirl, friction, turbocharger efficiency, and so on.
Michael Barber That's a very elaborate and thoughtful answer, thanks :) yeah, I haven't really given efficiency maps any thought before and you're totally right. If you look up these maps on the internet, you'll see indeed that the most efficient spot of the engine lies at the RPM of peak torque, but somewhat lower than full load. At higher RPMs, the efficiency gradually decreases, but there's a dramatic difference at low RPMs, where the available torque is minimal and the efficiency isn't all that great.
Definitely, in a car with a turbo, don't floor it in a high gear. However, in a NA car, flooring it in a high gear is actually efficient. You minimize pumping losses with a wide open throttle and minimize friction by being in a high gear. I drive this way and can get 40 - 45 mpg in a 1.5l engine. Toyota's hybrids including the Prius run at WOT over 90% of the time and the hybrid system tries to stay at low rpm as much as possible too. No problems with pre-ignition have been reported with their engines, although they do run at a lower compression than conventional engines too.
true about the Prius engines thing is the Prius taxis out here take off with their engines revving high while the regular priuses take off literally on their electric motors humming across the intersections ik now the Prius taxis get less MPG and more hell than the regulars kinda ironic since it's supposedly a 'green' car 😂😂😂😁😂
I actually did this in my new to me 2002 Mustang GT. I'm new to manual driving and had no idea this was bad. I was going around 55 MPH in 5th and slammed the pedal down, and my engine just kind of quit. No issues yet; I'm really praying I didn't do any major damage.
Could you explain the benefits and disadvantages of setting a lean or a rich a/f ratio?I am asking this because here in Brazil, we can easily add ethanol on the fuel tank, which would lead to a leaner mixture. Thanks
Even a larger motor like the 6.2L LS3, this applies. I have read posts by numerous Charger/Challenger guys who switch to the SS sedan and complain about it not having the same "low end torque". Hint: the LS3 was developed for the Corvette, it is a sports car motor, not a truck motor. Don't drop the hammer at 1200-1500 rpm and expect it to jump, that's lugging it. I let mine spin up at lower throttle settings to 2000-2500 before rolling (not hammering) the throttle open. Fully open by 2500... look around, you'll see this is the low end of what you see on dyno charts. Sports car engine, not a truck engine. It is intended to be spooled up. When going hard, keep it up above 3000 rpm. Not only is this better for the engine, it makes absolutely wonderful noises up there as well. Moseying down the highway at 1500 rpm, I generally won't use more than 30% throttle before downshifting to rev it up so I can open the throttle up in the happy part of the rev range.
Look, I worked at Denso as an powertrain engineer and I learned somethings there. 1- Toyota always use the oldest tech possible when it comes to embedded tech 2- Honda is terrified of BMEP 3- Denso tech follows Toyota wishes and Toyota does not like turbo engines. They it is too complicated and unnecessary. This is study you are using as reference was Toyota trying to discredit turbo engines that usually use more load at low RPM instead of more RPM and less load and thus showing the benefits of using a bigger NA engine because it is more durable. Don't buy this crap. This is just Toyota being obtuse. I had enough of them and left the group because of crap like this that I had listem. This sort of issues no longer apply to modern engines. Feel free to floor your TC engine at 1,5k RPM. If you want to have good reference look for the Germans and some of the Americans.
It is apropos when talking about Fords 2.3L Ecoboost with automatic transmission. I've had 2 rebuilds in 96,000 miles on my 2016 Mustang. Mostly, smart automakers are staying away from DISI engines. Fords larger ecoboost engines are direct and port injected. But not the 2.3. Mine is terrible at low end torque, and gets only a little better in sport mode. Can't wait to get mine out of the shop for a second time.
Great overview, but I have a bone to pick regarding your phrase "engine works harder, lower efficiency" Higher typical loads typically translate to higher efficiency, almost any NA engine BSFC map will show this trend (turbo BSFC maps get a bit more ugly). For this reason companies have attemped the "downspeeding" trend where lower speeds, higher loads creates greater overall economy. I will agree engine lugging, a transient nature in engines are moments of inefficiency due to engine calibration leaning towards performance for driveability (and also difficulty of calibration in these transitory regimes) Great video, I understand you have to explain all of these concepts to the general public in 10 minutes (props to you sir). I just imagined someone riding around in a car at 6000 rpm at 30mph, saying "nah it's cool, I saw on youtube engine works harder, it's less efficient"
Engineering Explained Ok, but now cars have direct injection, variable valve timing, complicated turbocharger systems, electric assist this, electric assist that. A catch can is medieval technology by comparison. if they made one for production vehicles, I think they would cost no more than, say, an air filter.
+tavi921 I think he made a video on it. Most consumers are too lazy or uninformed to know to drain it. It should be standard on performance cars or as an option on all others.
I definitely get the big picture here, but to me, the most important point would be to precisely define the term "lugging". For example, at what point on an x and y graph would you plot a "lug"? There are so many variables here; engine type, rpm, throttle position, throttle position delta over time, tuning parameters, gearing, etc, that it seems unlikely a definition exists. Personally, I don't "lug" my engine at least to the extent that I know when my engine is "lugging" simply because it doesn't "sound" very good and certainly doesn't "feel" very efficient.
Yeah, like shouldn't the engine manufacturer limit the torque at a given rpm so that the engine doesn't break in the first place? Because I haven't heard of any case where an engine broke for being lugged too much
Wait, is that still a thing? Isn't that controlled by the ECU? I mean, you can push the pedal as much as you want, but the ECU takes the decision on how much gas it will actually spray, right?
Great video! Good explanation. I was wondering, would you be able to do a video on what people call giving your car an "Italian tune up" every so often (once the engine is warmed up, raise the RPM's to 5,000/6,000). Does this benefit an engine at all? Does it help burn off any excess carbon?
Exactly, apart from this at low RPM the oilpump is providing less oil pressure and you have deposits forming at low RPM. If you just keep your engine RPM above 2000 then you won't have much deposits forming and you will have proper lubrication. One way to get rid of deposits is to just drive at high RPM. Such a pity modern cars change gears at way to low RPM just for 'fuel economy', and it's actually short-term fuel economy, when you start getting too much deposits because of the low RPM you will get worse fuel economy. But hey it was clean during the test so no manufacturer cares.
Although the above has a certain pragmatical basis, it is not always entirely the case. Most modern engines, with advanced engine ecu units and software, can detect knock, pinging and pre-ignition, through very sensitive knock sensor/s, catching it right just about it starts detonating, and thus reducing timing, and or richen afr at a specific load point/s.By reducing timing and in combination with richer afr, the ecu manages to minimize to the greatest degree possible or eliminates detonation and pre-ignition completely. Also the above conditions, vary a lot from setup to setup, as these adverse effects depend a lot on the materials used and on the design of the internal structure of cylinder block ( i.e cooling and oiling), cylinder head and ancillaries, pistons and rings, inlet and exhaust manifolds, turbocharger and intercooler used, degree of cylinder pressures and heat produced. It;s not about how early in the rev range boost is introduced, it's about how much early boost is introduced and if the rest of the setup/engine can cope with it. On some engines these effects are severe, on others, are almost non existant. Also I do not agree with the comment about the colder range plug not working, as it does.
"By putting in these higher gears your engine has to work harder, meaning it's going to be less efficient." - I don't think that's right. If you look up brake specific fuel consumption maps, engines tend to have best efficiency at around 80% throttle in the lower half of the RPM range, only tapering off below 1500rpm. Looking at a Satrun 1.9l BSFC map to get 30hp power 75% throttle at 1900RPM takes 40% less fuel than 25% throttle at 5000RPM.
+Ants Aasma in higher gears you have a mechanical disadvantage due to the gearing (your wheel torque is less). As a result of this, yes, your engine must work harder.
An engine working harder is only efficient if the work it's doing is efficient. Accelerating hard from a slow speed at a low rpm (aka high gear) isn't efficient. It takes a long time for the car to get up to speed even if you're flooring it. Instead you should drop a gear or two, which brings the rpms up into the 2500+ range, then floor it.
+FeedMyNeed That's why I said that you should look at the efficiency map. A joule of kinetic energy is a joule of kinetic energy, regardless of gearing. Most engines achieve near peak efficiency well below 2500 RPM and start to drop off after that.
One very important thing that was left out is lugging can also cause bearing failure. Since all of that load is put on the engine at such a low speed. The hydrodynamic layer of oil in between the bearings and rods or journals will get pushed out and in turn make flat spots on the bearings causing premature failure.
I drive a old 318 Magnum, low rpm is all the power, the engine falls flat on its face at 3k and its happiest putting around town at 800-1100. 80k miles doing this everyday and engine burns no oil, power hasn't went down, temperature gauge never moves when lugging it. Maybe if you're flooring it when the engine is literally stuttering and about to die, but he acts like of you don't downshift anytime you want to give it some throttle you're going to hurt it. Next time on engineering explained, "Why using your brakes is bad for your car"
Daily dose of knowledge. I'm no mechanic (nor do I intend to be one), but I love cars and it's awesome to learn about how things work. Awesome video once again!
Have to disagree with the beginning points regarding efficiency, at least when it comes to natural aspiration. It's proven that full throttle at a lower RPM is more efficient than part throttle at a higher RPM (to achieve same power output) because a partially closed throttle plate results in more vacuum and pumping losses.
thats the point, there is the efficiency for power per consumption and the mileage per consumption, he was talking about the power which u get out of the engine. thats often at 2000-3000rpm.-but when it comes to the consumption on distances then it will save gas to lower rpm to minimum to lower friction.
Been lugging my turbo cars since 1989 havent had an issue, they develop a better torque curve. I've out pulled friends with same vehicles and loads all because mine were run in thru letting them get down low in the rev range and lug like a truck.
I probably botched the intro like 12 times and at that point lost all excitement in filming haha. Not the first four words though, I've got that part down. Edit: Confirmed, am hostage.
Thanks for the info I'm new to turbo cars I just bought a 2017 Ford focus RS and I'm trying not to blow up my engine or damage it LOL your video was the only one I found that actually explained the situation and what not to do to avoid it thank you
You should include how it works on a rotary engine. Rotaries dont have timing. I know it is discontinued as of now but as an engineer standpoint it is interesting to learn about the rotary engine. Especially when there are a lot of mechanics that dont even know what a rotary engine is.
As a recent automotive school graduate and have taken many classes, specifically on drivability, emissions, and performance, I can say there's a lot of technically correct in this.
What about taking a right hand, slow corner (5-10mph) in 2nd or 3rd gear but not under considerable throttle? It is still quite similar to “lugging” correct?
diesel does not inject fuel till its time to burn. there is no such thing as preignition in diesel, they normally run by auto ignition from the heat of compression of the air charge, when fuel is injected the air is hot enough to make it burn instantly.
far cry of some of the diesel trucks I get to drive.(yes i know yer talking of gasoline eng..haha) I ran a mack that liked to be lugged at 1100 rpms pulling 60 tons of logs. My friend has a scania 730hp that lugs on a hill at 900~950 rpms (16 liter) pulling 60 tons. The engines just get down to low rpms - fuel pedal on the floor and happily "detonating" away pulling a big load. These new diesels using compacted graphite iron to take such pounding strain as you mention about "pressure buildup" with knocking. I used to run a dumptruck with a 392 gas jobby and would have to run it between 3400~4200 rpms pulling on a hill. It would knock anywhere from 1800~2200 rpms if you press throttle and not gear down to crank the engine speed up. great video, entertaining
If you look at the BSFC efficiency charts of most engines, you'll find that engine efficiency usually goes up with engine torque, and down with RPM. Most engines are their most efficient around the torque-peak-RPM while outputting a little below maximum torque. It's actually more efficient to to use a higher gear with more throttle than a lower gear with less throttle assuming you keep the acceleration rate the same.
i've had my 2004 A4 1.8T 6-speed manual since it was new, used Mobile 1 synthetic the whole life of the engine, 165k miles on it now, lug it all the time, even driving it up the mountains in Arizona in the summer. I'm pretty sure the ECU will not allow any condition that would damage the engine, once the engine can't sustain my speed i downshift. The car still purrs like a kitten.
The 1.8T uses so much fuel that LSPI would never even have a chance to occur. Not to mention that it's not direct injected so you're missing the point anyway.
It would be great to see how this compares with loading a diesel engine to prevent cylinder wall glazing. Also to see if there would be any fuel economy by running a diesel engine under load but not as much as flooring it.
Many do. The many people that have no clue about or feel for engines... which means most people. The problem is, those people don't watch this kind of videos anyway.
Could you do a video about the effects of different cylinder bank angles on V engines? It would be interesting to know why most V12s use 65° and most V8s have 90° bank angle and why nobody ever built something between those angles and a boxer like a V12 with 120° angle.
Lug??? I've never heard that word used in this context before and I've been driving cars for 50 years. To me a lug is a certain sort of sticky out thing or a word for carrying something heavy.
Wordreet, You said lug as in carrying something heavy, Like when you lug something heavy you move really slowly and rigidly because you have a massive amount of pressure weighing you down. It's the same principle with a engine, When you put a high load on your engine at a low rpm in a high gear, The amount of pressure you put on your engine is high so your engine is really lugging to carry the weight.
j0n0j0n0j No no, when I carry something heavy, I just chuck it up on my shoulder and off I go, muscles glistening in the sun, shades on, baseball cap backwards, whistling a merry tune with the thumb of my spare hand casually hooked in the waistband of my Levis. (are Levis even fashionable these days?)
Another key factor as to why full throttle at low RPM can cause issues is most engines have a higher effective volumetric efficiency at low-mid RPM, which in turn results in more fresh mixture in the cyclinder and thus higher peak pressures (during both compression and power stroke). This higher effective volumetric efficiency is mostly because of the increased amount of time the valve is actually open for for a given number of degrees duration on the camshaft, but it also comes form optimizations manufactures do to production cars (such as long intake runners) since most motors produce far more power than is needed for daily driving and so these vehicles spend 99% of their time at lower revs but still want to feel responsive and get good fuel mileage. Also while an oil catch can can help with droplets from the crack case breather, it doesn't help with oil from the turbo bearing, valve stem and blowby, all which get worse with wear (which is dramatically faster on power added or hard driven motors). So its not only cheaper\easier for engine packing to just limit max throttle position (or boost pressure for a turbo) at low RPM, but safer and doesn't really have any effect whent he car is driven correctly, be it on a daily commute (thus not high throttle) or around a track (thus higher RPM).
+taotoo2 Same here, I don't notice anything strange when flooring it in 5th at 50km/h (30mph approx). It's just slow, since it's a weak-sauce engine, but no strange acts.
OEMs also do what he suggested in the video which is to use a richer mixture at low RPM and high load. This is another reason not to lug the engine (it wastes fuel).
My car has the ultimate anti engine lug system. I have a custom performance muffler and if you lug the engine the drone is insane; it makes the whole car vibrate.
Another concern with lugging is, besides the engine, drivetrain wear. Especially if we're considering motorcycle engines which may have just single or twin cylinder engines. It's pretty common knowledge that for example a single cylinder bike can wear through chains and sprockets faster than, say, a four-cylinder (given an identical drivetrain, engine power characteristics and so on). And this is especially bad if the engine is lugged, when the power pulses of a large single-cylindered engine are timed much further apart than a multi-cylinder. So in effect the time between each application of torque to the sprockets and chain is very far apart. That will lead to the chain having more time to go slack between the power pulses.
+Engineering Explained flooring it while at Low RPM does not over heat, it actually causes a richer fuel:air ratio which yes makes it less efficient, but also actually runs cooler than a lean ration would because not as much of the fuel ignites due to the lack of air for the amount of fuel you're putting into the cylinders.
bzzzt!!! That's the sound of the winding of your cool hipster electruk motar generating an open SOMEWHERE on its winding. Result? SCRAP ENTIRE MOTOR (i.e. motor core labeld BCM and sent to OEM rewinding facility for MAJOR profit for what would be a tiny repair on an I.C.E.). But hey Eron Muskmellon said they were the cool new thing, so how could he possibly be wrong? He's not wrong about ANYTHING, EVAR!
ArchimedeanEye 2wd Teslas do have a gearbox. It is right next to the motor. Go to a showroom that has a bare chassis on display and you will see it. 4wd Teslas have two gearboxes.
wut? You can only lug a manual transmission, and it's becoming harder to find any truck with a manual. Automatics will always change the gear when you hit the gas.
Wow man you really put the best information on this platform. Your channel is certainly the most helpful to determine which truck I'll buy. Thanks so much.
I was actually using this 'technique' ( high gear, low RPM) to heat up my engine faster, especially now during the winter periods. My 2.2 L. high pressure turbo diesel needs 20 minutes of driving to start heating up normally in urban/ high traffic environments, however if I put it on 4th or 5th gear with 1400 rpm and push the gas pedal it starts heating up much more faster and the turbo works harder to compensate... And believe me, when outside is -17 degrees Celsius, you really want the car to heat up faster... haha
+Tsetso Zdravkov as far as lugging your engine, it's always a bad idea for gasoline engines as it can lead to pre-detonation; especially bad idea when the engine is cold. I certainly wouldn't recommend for diesel engines either, but since ignition is based on when fuel is injected, you likely don't need to worry about knock.
I just can't think of any other way to heat it up faster... maybe the old east-european technique with putting up a piece of carton in front of the radiator could also do the job... But this is a nasty type of solution. Those diesels were not meant to be driven during the cold winters. As for the carton, you can find and laugh at the example here: www.4tuning.ro/images/halloween-auto-made-in-rusia/halloween-auto-made-in-rusia-c470a1b32746075d6f-0-0-0-0-0.jpg : ))
LOL, I did the same with my moms old car in the winter. Of course I used the block heater before starting, but a 1.8l carb Camry does really not heat up quick. If the engine would have blown up mom would be 500€ poorer, as that is what the car was sold for in the end :)
go get a heat pump. it warms the coolant well plugged in overnight so that your motor has some warmth when you first start. it does a much better job then a simple block heater, If your -17 I would also be using your block heater as well
Lugging means higher internal peak temperatures in the cylinder. You could also burn an exhaust valve. Automatic transmissions are a good thing, especially when there are so many people driving around who have no clue about how their driving habits affect their vehicle.
What a rubbish! High or full throttle is close to the best efficiency at all RPM. Every specific fuel consuption diagramm shows that. And it doesn't heat up as much at lower RPM than at higher. The efficiency peaks at about 1/2 of max RPM. But If you don't need the power it's always more efficient to have much or full throttle at lower RPM than less throttle on higher RPM, cause efficiency drops with throttle (lower than appr. 90%). And to prevent knocking there's motor management, that sets ignition timing right. You are talking about engine technology from the 1960s, Sir. And lower speed of gases inside the engine is always better for homogenous distribution and so for even combustion.
I had so many questions about this on the "things you shouldn't do in turbo vehicles" and sadly none of them were answered here... 1. What specifically is considered lugging an engine? Is flooring it at 2k rpm lugging? 2.5k? 3k? I realize that number will vary engine to engine, but just a general rpm would be nice. 2. I assume you don't need to worry about this with diesels, as they kind of operate via pre-ignition anyways, but it's worth addressing anyways. 3. What about engines that run at inherently low rpms? Most vehicles made before WW1 couldn't even rev above 2k rpm!
I would like to add that GM found that engine oils with a high content of calcium may also cause LSPI...so use low Calcium oils that have some of the calcium replaced by other additives
Nice presentation, but I think the explanation about oil dilution missed the mark. Blowby will cause gasoline to mix with the oil in the sump. This mixing causes some of the lighter components of the oil to evaporate and go through the PCV system back to the intake manifold. So essentially the dilution increases the amount of oil droplets in the intake air stream. (It also causes intake valve deposits, which are a problem with direct injection engines.) One way to mitigate the problem is to use a low volatility oil (low NOACK number), like a synthetic, which has less lighter components and hence reduces the susceptibility to evaporation when mixed with gasoline. I'm not an expert in this, but I read some information about intake valve deposits that had this as an explanation.
TwilightTheShooter That's certainly true. But by modern I mean anything past 1990. Which is the vast majority of cars on the road. This video also seemed for focus on modern vehicles.
TheProPilot well since you cant drive it has nothing to do with you...its for the other half of the population, that can drive, and would get 600k out of a toyota motor...you may as well just buy a nice comfy dodge to wrap around telephone pole
Not crap at all. I drive an STI and there are plenty of clowns who destroy some part of the short block this way. The wastegate on the stock turbo is too small to accommodate a catlesss system even with stock injectors. In this case, there are hardware limitations that the software can't resolve. It's kind of funny actually. The turbine is small enough to allow overboost at low RPM, and again too small to relieve back pressure if you're trying to pass 120 mph. That being said, there are ways to program discrete ECU maps per gear, but I'm about 99.9999% sure that requires a 3rd party ECU. A lot of Supra owners actually do this so they won't spin their tires through the first 3.5 gears in drag races.
There should be a curve with throttle position and RPM on the X and Y axis, which tells which combination of RPM and throttle position would qualify as lugging. Because for the same RPM, some throttle position might not be lugging at all, while some higher RPM might clearly be lugging.
On the other hand, if you downshift, your engine rpm will increase which will lead to increase in friction in the engine which in turn will make the temperature rise and make parts wear faster, so yeah i think its safer to lug the engine, thanks for nothing.
I'll give you an example. In my teg I drive in 4th gear at 60 km/h with 2k rpm. The best thing to Do in this scenario is to downshift into 3rd if my speed starts to drop under 60km/h and then shift back into 4th if I'm trying to accelerate past 60. By shifting from 4th to 3rd going 55 km/h my rpms will go from 1.8k to about 2.8k rpm. The car drives best when it is at 2 k to 3.5 k rpms. So by downshifting it would put me in the optimal Rev range of the engine to give me the boost that I need, without having to lug the engine.
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You definitely shouldn't. Ive been lugging my engine around for a while and its really heavy. my back is killing me.
Keep on keepin on!
You just need to increase your RPM's and you'll feel better..
did you get the strong back perk?
I love this kind of jokes 😂😂😂
@@edbo10 fallout 76 reference….niiiiiiice
I have been a technician for 14 years, but the way Jason explains things, is second to none. I honestly do not know of anybody else that can do it as well as he does.
I appreciate the kind words Dan!
I second that .
Jason is a god among men
Lugging is a long-held tradition for high-efficiency cruising in aircraft and cars, although it's not as useful for cars since we do most cruising at high speed without tall enough gearing. Inner-cyinder temps and times leading to pre-ignition? You can hear and feel that. Longer-term temperature increase? There's a gauge for that. Obviously if you are making a pass, you don't want to lug, but for a completely different reason than the video states: you want to pass quickly!
I will happily continue ignoring the (bad and amateurish)advice given in this video. Negged!
@@JENKEM1000 it's not bad advice at all - giving a vehicle wide open throttle at low rpms (e.g. when you're barrelling down a highway) is bad, light pedal pressure is ok. Engine lugging is the former, not the latter. If you need to overtake at highway speeds and your engine is at low revs with more than 50% throttle that's going to create problems if you keep doing it, downshift instead.
Hi EE, great presentation on a topic that is so much misunderstood.
I did my engineering 35+ years before you and had the same conclusion but without the use of turbo, and the studies of Toyota and the computerized simulations that can be done nowadays. We (Ford) tested shock waves propagation on the rotating assembly, engine block, drive train (flywheel and damper), in a low rpm, high and low load, and high mixture (those were the sensors we had back then). We looked at the effect of lugging the engine and also at revving the engine under no load (like "kids and motorcyclists enjoy doing at red lights" and reported much greater stress on the engine components than at high rpm. The test scenarios eliminated air/fuel ratio imbalance, detonation, pre-ignition, as far as the technology of the day allowed. We also used engines that were "mint", all parts polished and cleaned for any debris, assembled to specifications by top technicians and engineers (truly yours included), optimal cam profile and ignition timing and test calculations with the best gear of that era. The consensus was like you mentioned plus we noticed extra vibrations, increased stresses on all parts, would decrease the life-cycle expectancy of most of the moving components of the engine/dyno linkage. We concluded that the engine (Ford 335 engine family) could take it, under the best conditions but the ultimate life of the engine/drive-train would be adversely affected. Did your studies looked at stresses on engine components aside without LSPI?
Thank you - Ciao L
These 'one take' explanations are very-well done without any falter. You must be an absolute savage at office engineering meetings.
they aren't full one take. edited
It kinda sounds like even he doesn't know what he's talking about. Normal people don't have race cars lol.
This explains two things:
- why I fouled the plug in our lawnmower (yanking the safety off and on at low revs is probably like "lugging" it), and
- why I'm hearing about fuel dilution in the oil in newer small-displacement turbo engines.
Nice use of ten minutes. Keep it up.
Really great to hear a thorough explanation of this and the science behind it. People thought I was crazy and trying to cause hysteria in EcoBoost owners when I talked about the dangers of LSPI in the EcoBoost Mustang. Some of the guys on the EcoBoost Mustang forums have also seen some correlation between LSPI and high calcium content in oils and the higher volatility of some oils. It seems like lower calcium content is safer for the EcoBoosts. The safer path for paranoid people like myself: don't void your warranty and/or get something naturally aspirated instead lol.
#FivePointOhLife
LSPI can pretty much happen in any car, it's just that it's more common in newer turbo engines because they use DI, which means higher compression ratios, and they generally use small turbos which spool much quicker, which means a lot of boost at low RPMs. LSPI is not just an ecostang or ecoboost issue, it applies to the new WRX, VWs, etc. I wouldn't even necessarily even call it an issue, it pretty much only occurs when you're doing something wrong. There can be flukes, but generally it's a driver issue, not something wrong with the car.
You didn't really see LSPI in old turbo engines because the compression ratios were lower and the turbos didn't really spool until like 4-5k+ rpm.
You could still have LSPI happen in NA, it's just not as likely. Lugging an NA engine is still horrible for it.
One of the issues is that turbos or big engines produce a lot of torque and that can mask the fact that you are lugging your engine. (because they accelerate fairly well) Obviously though, it's going to be much easier to lug an NA 4 cylinder vs a V8. (within reason)
Not trying to lecture you, just clarifying. :)
EE feel free to correct me if I'm wrong. You'd know more than me. lol
Will you also talk about rod loading?
connecting rod loading is pretty much what pre ignition/ knocking does in your motor. the combustion will be happening before top dead center on the ignition stroke and the flame from the ignition will meet the top of the piston before the piston is at top dead center and tries to force the piston back down as the piston is coming up to ignite when its supposed too, so its pushing back on the piston connecting rod which can nend connecting rods or even worse blow the piston out the bottom or side of the motor blowing the engine up :P but hopefully your engine will never knock that bad because the knock sensor can sense pre ignition before you can even hear the engine starting to knock and pull timing as needed
+CSmittyBurz This makes sense. I've never heard of this issue with the 3000gt VR4 guys. I've chugged along the "grape vine" in California plenty of times in a high gear at a low RPM with ~1-2lb of boost or so with no knock detected in my VR4. It must be because of the low compression and no DI.
Most people in Europe drive manual, most people in Europe don't know this and lug the engine on a daily basis.
This is very true
I'm sending this video to my friends and family, we have a few sub 1L 3-cyl turbo cars.
but it's easier to not lug in a manual since you can downshift
+iMiguelAOG can downshift an automatic too, if not, push pedal to floor, shoukd kick down a gear, two or three.
You know what? Most automatics are also lugging because fuel economy or something. not always willing to downshit
I’ve been learning how to drive a manual recently, and I’ve learned so much from your videos. Thank you so much
Absolutely love your explanations Jason. You cover everything quickly and efficiently and even throw some tips at the end, and it boggles my mind how you do all your videos in one take.
I've been a diesel technician for six years. Their are tests from the vehicle manufacturers that tell you to do a lug down in order to simulate a fully loaded trailer. When you do a lug down if you have a plugged doc or dpf, failing turbo or turbo waste gate, or failed egr valve or thermalanagement valve this test will let you check readings for boost and intake manifold pressures. If the vehicle hits a certain rpm and doesn't start acceleration under boost then you can identify the problem. So while it may not be good to do all the time there is still tests that require you to do a lug down
Still awesome video and explanations
Depends . Diesels don’t rev high to begin with, and they make all their torque in the low rev range which is a lot of torque dude to the long stroke. You can’t really lug a diesel. A gasoline engine with a turbo depending the size of the turbo there isn’t much torque down low due to a shorter stroke to be able to rev higher and make more horsepower. This is where issues occur
I enjoy watching many of your videos, but as an engine engineer, there are a few points I would like to comment on that are not very accurate in this video.
Regarding engine being less efficient when lugging, it is not completely accurate. First of all, it depends on if you are talking about overall efficiency or combustion efficiency. Regarding combustion efficiency, it is a balance between heat transfer loss (which is more prominent at lower RPM) and friction loss (which is more prominent at higher RPM), so the sweet spot is engine dependent (over-square vs under-square, how the wastegate/bypass logic works etc.), somewhere is the middle of the RPM range. But overall efficiency, which includes pumping loss, will tend to be higher at lower RPM since there is less pumping loss at lower RPM to achieve the same brake mean effective pressure (BMEP).
So it is all relative depending on how low of an RPM you call it lugging the engine.
The second point is that on your graph you have the spark timing after TDC, which is not very accurate. Most modern cars have the ignition timing before TDC, since SI engines have ignition delay, i.e. the charge does not immediately ignite after spark.
One last point is that you did not point it out explicitly, but this explanation is for SI engines. CI engines (diesel for example) has a different mechanism and there are a few points you pointed out here that would not apply to CI engines.
Also, there are many comments from the viewers that said the ECM could take care of it. I think it is good to clarify that unlike knock, pre-ignition is not as easy to handle as knock in an engine. The main logic to move away from knock is by retarding spark timing. but since pre-ignition is not triggered by the spark from the spark plug, it is fairly challenging for the ECM to handle it.
Good luck with your channel and the future videos.
Thank you for your insights!
Si stands for Spart Ignition engines that so require a spark to ignite air/fuel mixture - gaz(propane, CNG, LPG), gasoline, ethanol (E85), engines
Ci stands for compression ignition, let’s say Diesel engines
Cheers
Great precisions, right.
Concerning the TDC related spark advance I think Jason means the moment of combustion accuring so it’s simpler to explain without the firing delay...
Your insights are pretty much what I was thinking, too. I know that overall efficiency is usually higher when the engine is at lower RPMs and higher loads, which is what I usually try to do when I'm driving (sometimes more "aggessively" than I should, if you can call "accelerating as slowly as possible without stalling" aggressive). I'm now puzzled with this situation, how can I take advantage of the low RPM high load efficiency boost while still making sure I'm not damaging my engine by lugging it? Any insights?
I didnt read i just scrolled lel
I know exactly how a lugged engine feels; my boss expects me to do more work than I can.
You Rev matched your comment to your username pretty well!
what about diesels/turbodiesels? more or less prone to that? (since they obviously have alot more torque at lower rpm)
That's a great question
I always wonder if I'm lugging the engine on my diesel Volvo. The gearbox upshifts very early and even under medium acceleration at ~1200rpm, it doesn't downshift unless I jerk the accelerator to force it to. The engine's audibly humming louder and there's a bit of vibration. Is this bad?
+Oscar Lee If your car is shifting early I font think that's exceptionally bad? But it is odd. The audible noise is definitely not good. Go post and look on some forums before you ho spend any money at the mechanics. Or call Car Talk on NPR.
The base RPMs are just lower that's it. But you still shouldn't do it.
The noise can be described as a hollow sound that my other diesel car also makes when at low rpm, and a bit of load. I wouldn't worry about spending money on it since it's still under warranty.
So my last car was a Mazda CX-7 with the MZR2 Turbo. The Transmission on this vehicle would allow you to manually shift and you could go with WOT at very low RPM in higher gears. Being it was a single scroll turbo there was lag but it would pull pretty hard in the higher gears. It also produced a ton of smoke. Eventually the seal on the turbo blew. The engine later started having serious issues stalling and misfiring while dumping smoke out the exhaust. I did not have much done to it as I was looking for a new car and did not want to dump a ton of money into it. I was told the very thing that damaged the engine and the seal on the turbo was WOT at low RPM under load. The car I have now is also a turbo 4 but it will not allow you do this. If you floor the pedal at low RPM the transmission down shifts , even in sport mode. So I learned about this the hard way. Mechanic said, would you start from a dead stop in 4th gear?
I always wondered what happens when accelerating too fast in low RPMs. But you can hear the engine straining and it's common sense to avoid that situation.
Very good information. People have always told me that lugging my engine is damaging, and of course, there are very obvious reasons why it wouldn't be in my best interest to do so. However, I've never really believed any information I've read on car forums simply because nobody could back up their claims concerning the damages and risks involved in doing so. I've looked into the study done by Denzo and Toyota, and now I understand why this is bad.
Keep up the great work Jason. I learn a lot here. I've also picked up that book you recommended--Physics for Gearheads. My degree is in Physics, and my main struggle has been explaining in layman terms the physics of performance vehicles when my friends ask me various questions. Mainly because I like math too much. This has been a great resource in order for me to refine my language when explaining these concepts, and learn some new information myself.
Keep up the great work! I may have an unpopular opinion here, but I'd like to see some more math!
+Keita Linden happy to hear it! Every now and then I'll throw in some math. :)
Math scares me... My nightmares consist of repeating my senior year and being chased by algebra equations
Hey man, algrebra is tricky. I did well in Algebra I, Algebra II, and geometry, but once trig and calculus came along applying everything I learned in all of these classes was tough. It takes a lot of patience and practice, but once you get it, it's great fun. It's like solving a big puzzle.
Always am thinking that if I stay in the highest gear I'll get the best fuel economy but you are helping me change my mind
Not always the best policy. Drive in the engines optimum power band is the best in experience. Low revs doesn't necessarily benefit economy either. You need airflow to achieve good air:fuel mixing. This doesn't happen optimally at extremely low revs.
Also, the engines RPM is relative to the fuel consumption. Great statement @paulanderson79 !
Nick Wunnenberg well... yes and no
paulanderson79 true... Efficiency is the key to economy AND power. Too low of rpm and you are wasting fuel due to not enough air flow to burn it all. Too high of rpm and you are now ignoring the efficiency peak and going for peak power.
The very start of your peak torque curve will be the most fuel efficient for your car. Mine is from 3-4k (out of a 9.3k redline) below that and my torque band is very low, above that and my variable vavles begin opening to optimize performance and the car start to get richer AFR to make the most power rather than Torque
@@dustincomp1814 "variable valves" hmm?😜
How about diesel engines? Diesel cannot ignite the fuel too early because the fuel is not injected until the moment it's supposed to be burned. Of course, if you lug the engine low enough to cause vibrations higher flywheel (or dual mass flywheel) can take, you will cause huge stress to transmission. However, do you have a reason to state that the engine itself would be damaged by lugging the diesel engine? (Let's assume that we're speaking about direct injection turbo diesel engines here...)
The fact turbocharged engines are becoming very commonplace & many of them advertise their dynos with very beefy low end torque numbers. This probably gives the wrong impression that manual drivers won't need to downshift to pick up speed, hence the lugging.
2015 WRX here. If I'm traveling in top gear cruising on highway and want to floor it then I always downshift accordingly and then do upshifts all depending on what speed I am doing. Otherwise it will bog down. This is my first turbo and love it. This is me coming from my first car 1995 Ford Escort LX wagon then 2001 Civic. Both were 5-speed manuals but of course they had very low HP. Day and night difference with current car lol.
Yeah. You can have maximum torque and still be able to lug the engine. My daily driver is a small turbo diesel and while it has a ton of torque starting at 1200rpm it actually has very little power in that range. Means I can hold a speed at incredibly low rpm but if I need to accelerate - to the lower gear it is. I think the operative definition of lugging is to ask the engine for more power than it can deliver. You can have all the torque you want but if you try to exceed the power rating at a particular rpm you're essentially feeding the engine too much fuel. I guess people cannot grasp this "discrepancy" that you can have loads of torque but no power and think that they get more torque by pushing the pedal.
Klikkitse yep. Comes from good practice and feel to know to downshift accordingly then push pedal more to accelerate and upshift accordingly.
Umm you usually do get more torque by pressing the pedal actually.
You've made a car guy out of me...I'm pretty sure everyone that knows me is probably sick of hearing me talk about it by now, so thank you! :) ...also, as a new owner of a manual transmission vehicle, and it being the only stick I've ever driven (people don't own them these days, I had no other way to learn!) ...these videos have been ESSENTIAL to my driving...so, my engine and transmission thank you too!
If things like pre-ignition don't apply to diesel engines (which only take in air rather than airfuel mix) you should state this clearly in your video please. Here in Europe we use Diesel a lot.
Marcus T This applies only to semidiesels - that is, Diesel engines with a carburetting starting aid like kigas.
Lugging a diesel puts it in the power curve.
Good really in depth video of things that go wrong that the average driver will not be aware of. I believe that lugging does not only happen at full throttle as mentioned a few times but is generally what happens when you try to accelerate in too high a gear for your current speed. The engine may vibrate and could even cut off if extreme. Another negative effect of Lugging that I did not hear you mentioned is low oil pressure due to low engine speed. Low oil pressure can lead to increased wear on bearings and to have low oil pressure at a time when you are placing greater load cannot be a great idea. Additionally I have heard that it is well known in the automotive world that the ideal oil pressure is somewhat above what would trigger your oil light so when you get to the oil light stage things are worse than you might think. Of course there is material to wear and it is not an instant disaster but one that can be avoided by always being in the best gear which is why we drive a manual in the first place. Lazy shifters should switch to an auto. A true manual driver gets a thrill out of being in the best gear for the moment and beyond the moment by being proactive as the next gear is anticipated. This level of driving can only be achieved in an auto by connecting it to cameras and gps or the brain of the driver. Autos will always be reaction based compared to manual.
A good example of this is with diesel engines. car engines rarely run at full loads but diesels often do. A diesel in a semi truck or heavy equipment will run at full load for hours at a time. If you have a pyrometer you can watch the exhaust temp climb as the rpm falls below the power band. Soon after, if you continue lugging the motor, the fuel temp will climb on motors that have an internal fuel rail and coolant temps will climb. On tier 3's exhaust sooting will occur and cause Regen cycles. Eventually the ECU will fault for one of these.
A teir3 Caterpillar held at 1600 under full throttle for an hour will fault. Try it with a gas motor in a car.
When are buses come back the temps can reach 1000 F when its doi g some small regens lol but its nowhere near full load
basically it's OK to rev a petol engine higher, but you DON'T need to do this with a diesel engine, since the fuel is sprayed into the cylinders after peak compression and immediatly ignites.
So my fellow Europeans, don't worry, you've not been taught wrong if you drive your diesel engines at low RPM, you're helping the environment ;)
I was about to ask that, because most large diesel engines are really slow, trucks are best at 1-1.5krpm, tractors aren't known for revving high as well. I think he really should've specified what engines this applies to.
@@kristapsjj8520 i have a range rover evoque which has a 2 litre diesel engine (163'500km). when i drove around 52km/h the engine rpm were at around 1.2k, it started to make a vibrating sound. over 1400rpm this didn't happen. Today I did some pulls on full throttle, which the car basically never experienced in its lifetime, and the vibrating noise was gone when the car was operating on such low rpm
@@c190gtc I can only speak for my engine. The D5 is notorious for soot. After driving for 500km as a grandma it's good to rev it once in a while and get all of that crud out of the exhaust etc.
Still lugging them below 1500 rpm destroys dual mass flywheels, especially in a 4 cylinder
Not the main reason. Diesels make a ton of torque in the lower rev range due to a longer stroke, they make power down low.
When I was allot younger I would do this with one of my big single cylinder motorbikes as it would make an awesome groundshaking thumping sound when in 5th gear and at low speed with the throttle wide open. When I came to do the first oil change there were shards of metal in the filter and sump. Lesson learnt.
That... Shouldn't happen. That's something else causing catastrophic failure.
Source: Ride and Repair high performance dirtbikes/motorcycles.
thats not the reason... cant be, Liam 4.0 agreed
Sounds more like a fucked up tranny (pun partially intended). It's amazing how randomly people link incidents and causes. If you rev your vehicle into the limiter directly after a cold start, and then a minute later your headlight fails, do you really think that's cause and effect?
At low rpm under heavy load, the velocity of the intake charge is quite slow.
The intake charge helps cool the valves and if the engine is kept under a heavy load at low rpm, this could raise the combustion chamber temperature leading to pre ignition. Think of this another way: Engine manifold vacuum. When the intake manifold vacuum diminishes (heads towards zero) the incoming velocity is also substantially reduced. Keep manifold vacuum high and the engine is happy.
There was a time when some cars actually had as a factory option a so called economy (vacuum) gauge. Keeping the vacuum high resulted in the best fuel economy. A boost gauge will show vacuum and boost, it is easy to tell why you don't have boost when you have wide open throttle at low rpm. The turbocharger requires reasonable pressure of exhaust to spin up, without this your stuck in the land of diminished intake manifold vacuum.
Some standby generator sets are run so hard that the valves will burn in as few as 100 operating hours. This type of load is akin to continuously driving up hill, towing a trailer at wide open throttle. This is another reason vehicles have transmissions.
Let engines rev but always leave some throttle in reserve, if one must hold the throttle wide open then you are in to high of a gear. It really is about load management, and to some extent why vehicles have automatic transmissions ;>)
Anyone who has owned any 2.3 mazdaspeed or CX knows about avoiding Lugging if they want to keep their con rods.
hellobooom
Lol
I've known some people to do this deliberately because they think higher gear = lower engine RPM = lower fuel consumption = better economy. I can't stand it as you can feel the engine labouring rather than pulling strong, it's inefficient and I'm confident there's no economical benefit. But I could be wrong. It could be great if you could look into this perspective of "lugging" an engine as well.
The rest of the story is that the Toyota Denso research (which all major automobile manufacturers either had access to or conducted themselves) was aimed at developing timing/fuel/air mappings that can mitigate and/or outright avoid the heat/pressure conditions resulting from lugging. If you drive a late model car with a small-displacement, turbocharged engine the computer simply won't allow you to cause damage to the engine by simply opening the throttle under any combination of throttle position/RPM.
Bottom line: If you drive a race car and/or a car with custom computer tuning there are rare conditions under which you might cause damage and/or excessive wear to your engine by lugging it. And if you're driving such a car you probably already know this. For everyone else, don't worry about it, the computer won't allow you to damage your engine by stepping hard on the gas in at low speed in a high gear.
I drive a 2016 Ford Mustang Ecoboost. It is 2.3L direct injected, turbo charged. NOT with port injection also. It has blown up twice in 96,000 miles. WITH a catch can. LSPI was probably the ultimate cause, but as the ECU brings the engine to a knock then retards timing, its knocking all the time. Since the DISI engines do not scrub deposits on the valves with gasoline going over them, you have a great source for hot spots in the cylinder.
@@Orcinus1967 If there were a widespread problem with stock engines blowing up we would know about it. There are literally millions of these engines in operation around the world. Almost all of the catastrophic failures I've read about involve modified software.
@@mwsletten In my case, a 2016 EB Mustang, I purposefully did not "tune" my car using modified software. I had a 100,000 mile CPO warranty to protect. I have found much evidence of the engine having problems, especially with cylinder # 3. Chevy, Ford, major manufacturers, all do not have a problem with 2-3% of their engines being bad. It is an acceptable level, and for the most part, they fix stuff under warranty, as they have fixed mine. Twice. I re-upped and got another 43,000 miles on an extended warranty, to 2024 or 143,000 miles. I am now at 97,000 miles. 2% of 1 million engines is 20,000. Ford does not want to discuss what is wrong with the 2.3L EB. I have to draw out of my service department what failed on my car, and then its never exactly what went wrong. "The heads", for example. When you say "engines" it helps to be specific. It is not the same as other EB engines. Most people aren't on forums about specific engines. And when they are I always find misinformation from supposed experts, and folks who haven't even owned a Ford of any sort, for 20 years. Of course the average person may not have an interest in cars. So even if they did have a problem, you would never hear about it, especially if they were provided a loaner car and it was fixed under warranty. Which 2.3L Ford do you drive BTW?
@@Orcinus1967 said: "I have found much evidence of the engine having problems, especially with cylinder # 3. Chevy, Ford, major manufacturers, all do not have a problem with 2-3% of their engines being bad."
Sorry to hear about the issues you've had with your car. I don't believe your experience is common.
Ford just chose the 2.3L EcoBoost for use in the Ranger and the new Bronco, two vehicles Ford expects to sell very well. That's a helluva a vote of confidence in an engine. Seems crazy Ford would do that with an engine it doesn't believe is rock solid.
It also seems crazy there are no stories in the press about customer complaints regarding the 2.3L EcoBoost. Ford just took a major financial hit on DCTs in its Focus and Fiesta model cars. The motoring press was all over the story as soon as customers started complaining, way back in 2011 when the DCT was first introduced. Where are the press reports about problems with the 2.3L EcoBoost, an engine that's been in service since 2015?
Here are a couple of questions:
1. What is the actual failure rate of the (unmodified) 2.3L EcoBoost engine?
2. What is the failure rate industry-wide for small displacement turbocharged engines from all manufacturers?
That's the data you need to determine reliability of the 2.3L EcoBoost engine. I can tell you that Consumer Reports rates reliability of Ford's 2.3L EcoBoost as above average. That's based on actual customer surveys.
I have Mustang EcoBoost. No significant engine problems after 40K. The only issue so far was a small oil leak around the valve cover which was repaired under warranty.
@@mwsletten I agree with you that if it was a major problem it would make the headlines, somewhere. If not NHTSA. But there are a lot sexier narratives running these days. Those being cops shooting blacks, and covid. These engines do blow up, and, like you said, especially if you take the safety stops off, as with an after market tune, or if you decide to pump up the horses with bigger intakes and turbos etc, but not the internals by putting in better pistons and connecting rods etc. What I have been told by 1 mechanic outside of Ford is that some companies have backed out of direct injection, the technology just not being up to the task, yet. Hopefully Ford has gained experience from the engines that have blown up, and fixed any issues. Today they make the Hi Performance 2.3L. They took some safety stops off there. Changed the revs and the horsepower. They must have learned something. Years ago, 2018? I had asked a guy at Mountune (Mountune are a race engine and road-car performance specialist who alongside Ford have developed critically acclaimed packages that boost not only output but also performance.) if they could work on my 2.3 Mustang engine. They were advertising they would work on it at the time, online. When I called on the phone, however, the answer was "NO". Only the Ford Focus ST and RS and Fiesta ST. They would not say why they would not work on the Mustang 2.3L engine. Most likely they did not want to jeopardize their relationship with Ford. To me, from my personal experience, at Ford dealers and at my personal mechanic (recommended by a Ford parts salesperson) that says "there is an issue, and we are not discussing it due to the legal and cost ramifications of a potential recall". And, another thing I've heard over and over is "I have a relationship with Ford, I'm not going to jeopardize that relationship", even if it's only someone selling me a set of hood stripes in a color Ford does not want me to put on my car. I am more skeptical than you. Ugh. I'm going to clean my catch can.
Cheers and good luck with your EB! I love my car and I'm keeping it til I find a V8 Stang with Magneride, used. Then I can deal with the ticking engine thing on the 5.0!
I just got my first car a few months ago, been lugging the engine a lot. Thank god I saw this video
Great explanation! Now can you explain Why You Should Never Rev you engine?
Haha
Lol
Lugging the engine usually only occurs at VERY low engine rpm, like below 1,000 or if your in 5th gear going 40mph (5spd). If when you floor it it doesn't sound like it's about to stall your fine.
uncreativename I don't think you got the joke lol
Just watch the video but in summary it increases engine temp and can cause blowbly and all sorts of bad sheninigans. And it might use more fue because the engine is not efficient while lugging.
Mindblowingly logical. You have the best job in the world. Would have been nice to hear how lugging affects a diesel engine as well...
All modern turbo engines has full torque in 1300-1500 rpm (in fact 2000rpm) so all you need to do is set Sport mode in tranny and it will keep it over 2000rpm. In manual yes it can damage engine in some way.
Not "all" modern turbo engines
well the smaller turbodiesels don't have full torque at rpm's that are so low, mine is a little lazy under 1700 rpm (1.3 Multijet)
you're talking out of your ass....
Жора, а на атмосферных это тоже касается ?
My car hits peak torque around 5000RPM, and I would consider the 4B11 a "modern turbo engine." It cold idles around 1500, so I'm not sure where you got that statement of yours.
Why do you say that the efficiency is lower when the engine has to work hard? You are the first person I ever heard saying such a thing. According to my professors and a book "Introduction to Internal Combustion Engines" by Richard Stone among other sources, every engine is more efficient under full load than it is under part-load. I.e. if the engine has to work harder - it is working more efficiently. This is especially true with traditional petrol engines with a throttle valve. Which brings me to my next question. Does this lugging problem also affect direct injection diesel engines? You never seem to take diesels into account when talking about such matters.
I believe this is particularly true for gasoline/petrol engines thanks to the throttle, as you noted -- at part load the restriction and pumping losses reduce efficiency. At (nearly) full load, this problem goes away. At *full* load however, your engine management might make the mixture richer for that last bit of extra power, reducing efficiency again.
That's not the whole story though -- it's more of a 2-dimensional problem. So, for a given RPM, you do get more efficiency with more throttle. BUT, for a given throttle position, you'll get varying efficiency with engine RPM. Apparently, the best efficiency may be around peak torque. There are probably instances where you'd be better off at 75% throttle and the "right" RPM than 90% throttle at a very low speed.
I guess a given engine will have an efficiency map as a function of throttle and RPM. Things to think about would be intake tuning and exhaust scavenging, valve clearances and swirl, friction, turbocharger efficiency, and so on.
Michael Barber That's a very elaborate and thoughtful answer, thanks :) yeah, I haven't really given efficiency maps any thought before and you're totally right. If you look up these maps on the internet, you'll see indeed that the most efficient spot of the engine lies at the RPM of peak torque, but somewhat lower than full load. At higher RPMs, the efficiency gradually decreases, but there's a dramatic difference at low RPMs, where the available torque is minimal and the efficiency isn't all that great.
i'm right with you on this, you beat me to it.
My 2014 Ford Focus ST with 22000 km's on the clock blew up two day's ago!
Definitely, in a car with a turbo, don't floor it in a high gear. However, in a NA car, flooring it in a high gear is actually efficient. You minimize pumping losses with a wide open throttle and minimize friction by being in a high gear. I drive this way and can get 40 - 45 mpg in a 1.5l engine. Toyota's hybrids including the Prius run at WOT over 90% of the time and the hybrid system tries to stay at low rpm as much as possible too. No problems with pre-ignition have been reported with their engines, although they do run at a lower compression than conventional engines too.
true about the Prius engines thing is the Prius taxis out here take off with their engines revving high while the regular priuses take off literally on their electric motors humming across the intersections ik now the Prius taxis get less MPG and more hell than the regulars kinda ironic since it's supposedly a 'green' car 😂😂😂😁😂
My challenger gets 25 mpg on the highway in 6th gear. It's great!
@@yanrodgers7775lmao
I actually did this in my new to me 2002 Mustang GT. I'm new to manual driving and had no idea this was bad. I was going around 55 MPH in 5th and slammed the pedal down, and my engine just kind of quit. No issues yet; I'm really praying I didn't do any major damage.
Could you explain the benefits and disadvantages of setting a lean or a rich a/f ratio?I am asking this because here in Brazil, we can easily add ethanol on the fuel tank, which would lead to a leaner mixture. Thanks
Rich mixture wastes fuel but makes the engine run cooler. Lean mix is good for economy but makes the cylinder head run at an increased temperature.
Even a larger motor like the 6.2L LS3, this applies. I have read posts by numerous Charger/Challenger guys who switch to the SS sedan and complain about it not having the same "low end torque". Hint: the LS3 was developed for the Corvette, it is a sports car motor, not a truck motor. Don't drop the hammer at 1200-1500 rpm and expect it to jump, that's lugging it. I let mine spin up at lower throttle settings to 2000-2500 before rolling (not hammering) the throttle open. Fully open by 2500... look around, you'll see this is the low end of what you see on dyno charts. Sports car engine, not a truck engine. It is intended to be spooled up. When going hard, keep it up above 3000 rpm. Not only is this better for the engine, it makes absolutely wonderful noises up there as well. Moseying down the highway at 1500 rpm, I generally won't use more than 30% throttle before downshifting to rev it up so I can open the throttle up in the happy part of the rev range.
Look, I worked at Denso as an powertrain engineer and I learned somethings there.
1- Toyota always use the oldest tech possible when it comes to embedded tech
2- Honda is terrified of BMEP
3- Denso tech follows Toyota wishes and Toyota does not like turbo engines. They it is too complicated and unnecessary.
This is study you are using as reference was Toyota trying to discredit turbo engines that usually use more load at low RPM instead of more RPM and less load and thus showing the benefits of using a bigger NA engine because it is more durable.
Don't buy this crap. This is just Toyota being obtuse.
I had enough of them and left the group because of crap like this that I had listem.
This sort of issues no longer apply to modern engines. Feel free to floor your TC engine at 1,5k RPM.
If you want to have good reference look for the Germans and some of the Americans.
It is apropos when talking about Fords 2.3L Ecoboost with automatic transmission. I've had 2 rebuilds in 96,000 miles on my 2016 Mustang. Mostly, smart automakers are staying away from DISI engines. Fords larger ecoboost engines are direct and port injected. But not the 2.3. Mine is terrible at low end torque, and gets only a little better in sport mode. Can't wait to get mine out of the shop for a second time.
I could honestly listen to Jason all day, everyday, he's so knowledgeable, plus, I'd learn so much, thanks for the best schooling of my life Jason
Is any of this applicable to modern Direct injection Turbo Diesels?
not at all... engine management systems change variables when they sense knock...
I don't think so, I think all this is pretty vague on diesels, considering they sometimes peak torque at 1700 rpm
Great overview, but I have a bone to pick regarding your phrase
"engine works harder, lower efficiency"
Higher typical loads typically translate to higher efficiency, almost any NA engine BSFC map will show this trend (turbo BSFC maps get a bit more ugly). For this reason companies have attemped the "downspeeding" trend where lower speeds, higher loads creates greater overall economy.
I will agree engine lugging, a transient nature in engines are moments of inefficiency due to engine calibration leaning towards performance for driveability (and also difficulty of calibration in these transitory regimes)
Great video, I understand you have to explain all of these concepts to the general public in 10 minutes (props to you sir). I just imagined someone riding around in a car at 6000 rpm at 30mph, saying "nah it's cool, I saw on youtube engine works harder, it's less efficient"
I wonder why manufacturers don't pot catch cans on their cars from the factory. It's not even expensive.
Because consumers don't want another maintenance item to deal with, and I suppose the added cost, however minor adds up across millions of cars.
Why can't they just drain the oil right back into the oil pan?
Engineering Explained
Ok, but now cars have direct injection, variable valve timing, complicated turbocharger systems, electric assist this, electric assist that. A catch can is medieval technology by comparison. if they made one for production vehicles, I think they would cost no more than, say, an air filter.
+tavi921 I think he made a video on it. Most consumers are too lazy or uninformed to know to drain it. It should be standard on performance cars or as an option on all others.
no1ymfan1
I know, but most people have the oil changed by a mechanic anyway.
I definitely get the big picture here, but to me, the most important point would be to precisely define the term "lugging". For example, at what point on an x and y graph would you plot a "lug"? There are so many variables here; engine type, rpm, throttle position, throttle position delta over time, tuning parameters, gearing, etc, that it seems unlikely a definition exists. Personally, I don't "lug" my engine at least to the extent that I know when my engine is "lugging" simply because it doesn't "sound" very good and certainly doesn't "feel" very efficient.
Doesn’t EFI inhibit the ability to “lug” an engine by limiting the amount of fuel supplied when you step on the gas at low RPM?
Yeah, like shouldn't the engine manufacturer limit the torque at a given rpm so that the engine doesn't break in the first place? Because I haven't heard of any case where an engine broke for being lugged too much
Wait, is that still a thing? Isn't that controlled by the ECU? I mean, you can push the pedal as much as you want, but the ECU takes the decision on how much gas it will actually spray, right?
Great video! Good explanation. I was wondering, would you be able to do a video on what people call giving your car an "Italian tune up" every so often (once the engine is warmed up, raise the RPM's to 5,000/6,000). Does this benefit an engine at all? Does it help burn off any excess carbon?
All I can say is that you inspire and motivate me and for sure thousands of others! Big thanks!
Exactly, apart from this at low RPM the oilpump is providing less oil pressure and you have deposits forming at low RPM.
If you just keep your engine RPM above 2000 then you won't have much deposits forming and you will have proper lubrication.
One way to get rid of deposits is to just drive at high RPM.
Such a pity modern cars change gears at way to low RPM just for 'fuel economy', and it's actually short-term fuel economy, when you start getting too much deposits because of the low RPM you will get worse fuel economy. But hey it was clean during the test so no manufacturer cares.
Welp thats usually when i shift in my brz (2k rpm) and on the highway im between 3-3.5k rpm so passing is easy and simple.
Although the above has a certain pragmatical basis, it is not always entirely the case. Most modern engines, with advanced engine ecu units and software, can detect knock, pinging and pre-ignition, through very sensitive knock sensor/s, catching it right just about it starts detonating, and thus reducing timing, and or richen afr at a specific load point/s.By reducing timing and in combination with richer afr, the ecu manages to minimize to the greatest degree possible or eliminates detonation and pre-ignition completely. Also the above conditions, vary a lot from setup to setup, as these adverse effects depend a lot on the materials used and on the design of the internal structure of cylinder block ( i.e cooling and oiling), cylinder head and ancillaries, pistons and rings, inlet and exhaust manifolds, turbocharger and intercooler used, degree of cylinder pressures and heat produced. It;s not about how early in the rev range boost is introduced, it's about how much early boost is introduced and if the rest of the setup/engine can cope with it. On some engines these effects are severe, on others, are almost non existant. Also I do not agree with the comment about the colder range plug not working, as it does.
"By putting in these higher gears your engine has to work harder, meaning it's going to be less efficient." - I don't think that's right. If you look up brake specific fuel consumption maps, engines tend to have best efficiency at around 80% throttle in the lower half of the RPM range, only tapering off below 1500rpm. Looking at a Satrun 1.9l BSFC map to get 30hp power 75% throttle at 1900RPM takes 40% less fuel than 25% throttle at 5000RPM.
+Ants Aasma in higher gears you have a mechanical disadvantage due to the gearing (your wheel torque is less). As a result of this, yes, your engine must work harder.
+Engineering Explained my point was rather that an engine working harder is generally more efficient, not less.
An engine working harder is only efficient if the work it's doing is efficient. Accelerating hard from a slow speed at a low rpm (aka high gear) isn't efficient. It takes a long time for the car to get up to speed even if you're flooring it. Instead you should drop a gear or two, which brings the rpms up into the 2500+ range, then floor it.
+FeedMyNeed That's why I said that you should look at the efficiency map. A joule of kinetic energy is a joule of kinetic energy, regardless of gearing. Most engines achieve near peak efficiency well below 2500 RPM and start to drop off after that.
One very important thing that was left out is lugging can also cause bearing failure. Since all of that load is put on the engine at such a low speed. The hydrodynamic layer of oil in between the bearings and rods or journals will get pushed out and in turn make flat spots on the bearings causing premature failure.
I drive a old 318 Magnum, low rpm is all the power, the engine falls flat on its face at 3k and its happiest putting around town at 800-1100. 80k miles doing this everyday and engine burns no oil, power hasn't went down, temperature gauge never moves when lugging it. Maybe if you're flooring it when the engine is literally stuttering and about to die, but he acts like of you don't downshift anytime you want to give it some throttle you're going to hurt it. Next time on engineering explained, "Why using your brakes is bad for your car"
yeah because it's an old big v8 that doesn't have enough power to hurt itself
Daily dose of knowledge. I'm no mechanic (nor do I intend to be one), but I love cars and it's awesome to learn about how things work. Awesome video once again!
Have to disagree with the beginning points regarding efficiency, at least when it comes to natural aspiration. It's proven that full throttle at a lower RPM is more efficient than part throttle at a higher RPM (to achieve same power output) because a partially closed throttle plate results in more vacuum and pumping losses.
Karl L. Yeah, 80% throttle at low rpm should get you the maximum efficiency.
thats the point, there is the efficiency for power per consumption and the mileage per consumption, he was talking about the power which u get out of the engine. thats often at 2000-3000rpm.-but when it comes to the consumption on distances then it will save gas to lower rpm to minimum to lower friction.
Agreed. Same aspects can apply to a turbocharged engine before it gets into boost.
Been lugging my turbo cars since 1989 havent had an issue, they develop a better torque curve. I've out pulled friends with same vehicles and loads all because mine were run in thru letting them get down low in the rev range and lug like a truck.
Is it me or does his "Hello everyone and welcome" not have as much energy as it used to? Maybe he needs a service to get better performance, lol.
or maybe he is slowly dying lol
Probably being held hostage and bring forced to make videos
I probably botched the intro like 12 times and at that point lost all excitement in filming haha. Not the first four words though, I've got that part down.
Edit: Confirmed, am hostage.
Are you offering to service him :)
A tank or two of SUNOCO 125 octane and a bunch of laps on the racetrack. should do the trick.
Thanks for the info I'm new to turbo cars I just bought a 2017 Ford focus RS and I'm trying not to blow up my engine or damage it LOL your video was the only one I found that actually explained the situation and what not to do to avoid it thank you
I only use fifth gear and always go full throttle.
+500k miles, no issues.
You should include how it works on a rotary engine. Rotaries dont have timing. I know it is discontinued as of now but as an engineer standpoint it is interesting to learn about the rotary engine. Especially when there are a lot of mechanics that dont even know what a rotary engine is.
You don't have to worry about this in modern automatic cars though. Usually they drop a gear or two when you floor it at a high gear
TehZured WOW...! really..?
I know right dude! Completely unknown!
my commuter will downshift from 3rd to 1st if you floor it at 20mph its hilarious
wtf 1st?
even older cars had kickdown mode - usually needed an actual cable to the transmission :D
As a recent automotive school graduate and have taken many classes, specifically on drivability, emissions, and performance, I can say there's a lot of technically correct in this.
LOL "Tune for rich af mixture"
What about taking a right hand, slow corner (5-10mph) in 2nd or 3rd gear but not under considerable throttle? It is still quite similar to “lugging” correct?
how does this differ with a diesel engine?
diesel does not inject fuel till its time to burn. there is no such thing as preignition in diesel, they normally run by auto ignition from the heat of compression of the air charge, when fuel is injected the air is hot enough to make it burn instantly.
You can get High EGT's with a diesel which will cause excessive heat. That can cause broken rings on a diesel.
I always wonder if the guys making their diesel puke black smoke monitor EGTs ... I bet they don't
far cry of some of the diesel trucks I get to drive.(yes i know yer talking of gasoline eng..haha) I ran a mack that liked to be lugged at 1100 rpms pulling 60 tons of logs. My friend has a scania 730hp that lugs on a hill at 900~950 rpms (16 liter) pulling 60 tons. The engines just get down to low rpms - fuel pedal on the floor and happily "detonating" away pulling a big load. These new diesels using compacted graphite iron to take such pounding strain as you mention about "pressure buildup" with knocking.
I used to run a dumptruck with a 392 gas jobby and would have to run it between 3400~4200 rpms pulling on a hill. It would knock anywhere from 1800~2200 rpms if you press throttle and not gear down to crank the engine speed up.
great video, entertaining
lol i have a feeling hes gunna start telling us starting ur car when its off is damaging the engine
Most damage is caused when starting...........
@jared p: Did you ever see a car failing when it was not even running? ;-)
jared p you should start your car until the oil has come up to operating temperature.
this possible but only if you don't start it and let it sit for long periods of time.
Have you ever heard of Ferrari?
If you look at the BSFC efficiency charts of most engines, you'll find that engine efficiency usually goes up with engine torque, and down with RPM. Most engines are their most efficient around the torque-peak-RPM while outputting a little below maximum torque. It's actually more efficient to to use a higher gear with more throttle than a lower gear with less throttle assuming you keep the acceleration rate the same.
i've had my 2004 A4 1.8T 6-speed manual since it was new, used Mobile 1 synthetic the whole life of the engine, 165k miles on it now, lug it all the time, even driving it up the mountains in Arizona in the summer. I'm pretty sure the ECU will not allow any condition that would damage the engine, once the engine can't sustain my speed i downshift. The car still purrs like a kitten.
One of VW's better engines. The 1.8T is well proven and well regarded.
The 1.8T uses so much fuel that LSPI would never even have a chance to occur. Not to mention that it's not direct injected so you're missing the point anyway.
It would be great to see how this compares with loading a diesel engine to prevent cylinder wall glazing. Also to see if there would be any fuel economy by running a diesel engine under load but not as much as flooring it.
Who accelerates from low rpm very hard ? If you are racing you are well off the power curve. If you are a hyper miler you gradually accelerate.
Many do. The many people that have no clue about or feel for engines... which means most people. The problem is, those people don't watch this kind of videos anyway.
Could you do a video about the effects of different cylinder bank angles on V engines?
It would be interesting to know why most V12s use 65° and most V8s have 90° bank angle and why nobody ever built something between those angles and a boxer like a V12 with 120° angle.
Lug??? I've never heard that word used in this context before and I've been driving cars for 50 years. To me a lug is a certain sort of sticky out thing or a word for carrying something heavy.
It's an EXTREMELY common term in the automotive world.
Well dammit! I'd better get over there and tell 'em to stop it!!
Wordreet, You said lug as in carrying something heavy, Like when you lug something heavy you move really slowly and rigidly because you have a massive amount of pressure weighing you down. It's the same principle with a engine, When you put a high load on your engine at a low rpm in a high gear, The amount of pressure you put on your engine is high so your engine is really lugging to carry the weight.
j0n0j0n0j
No no, when I carry something heavy, I just chuck it up on my shoulder and off I go, muscles glistening in the sun, shades on, baseball cap backwards, whistling a merry tune with the thumb of my spare hand casually hooked in the waistband of my Levis.
(are Levis even fashionable these days?)
That's the word I couldn't remember! :¬D
Another key factor as to why full throttle at low RPM can cause issues is most engines have a higher effective volumetric efficiency at low-mid RPM, which in turn results in more fresh mixture in the cyclinder and thus higher peak pressures (during both compression and power stroke). This higher effective volumetric efficiency is mostly because of the increased amount of time the valve is actually open for for a given number of degrees duration on the camshaft, but it also comes form optimizations manufactures do to production cars (such as long intake runners) since most motors produce far more power than is needed for daily driving and so these vehicles spend 99% of their time at lower revs but still want to feel responsive and get good fuel mileage.
Also while an oil catch can can help with droplets from the crack case breather, it doesn't help with oil from the turbo bearing, valve stem and blowby, all which get worse with wear (which is dramatically faster on power added or hard driven motors). So its not only cheaper\easier for engine packing to just limit max throttle position (or boost pressure for a turbo) at low RPM, but safer and doesn't really have any effect whent he car is driven correctly, be it on a daily commute (thus not high throttle) or around a track (thus higher RPM).
Why doesn't the car just limit how far open the throttle can be at low revs?
Newer car's with drive by wire most likely do. Without drive by wire, it's impossible for the computer to control it.
Adam Harrington I suspected that was the case nowadays - I can't get my car to complain much if I floor it at low revs.
YYZpresto Presumably you've removed your starter motor and syncromesh etc
+taotoo2 Same here, I don't notice anything strange when flooring it in 5th at 50km/h (30mph approx). It's just slow, since it's a weak-sauce engine, but no strange acts.
OEMs also do what he suggested in the video which is to use a richer mixture at low RPM and high load. This is another reason not to lug the engine (it wastes fuel).
My car has the ultimate anti engine lug system. I have a custom performance muffler and if you lug the engine the drone is insane; it makes the whole car vibrate.
I was just lugging my engine when driving home from work… oops.
Another concern with lugging is, besides the engine, drivetrain wear. Especially if we're considering motorcycle engines which may have just single or twin cylinder engines. It's pretty common knowledge that for example a single cylinder bike can wear through chains and sprockets faster than, say, a four-cylinder (given an identical drivetrain, engine power characteristics and so on). And this is especially bad if the engine is lugged, when the power pulses of a large single-cylindered engine are timed much further apart than a multi-cylinder. So in effect the time between each application of torque to the sprockets and chain is very far apart. That will lead to the chain having more time to go slack between the power pulses.
Incorrect in some situations, like offroad.
+Engineering Explained flooring it while at Low RPM does not over heat, it actually causes a richer fuel:air ratio which yes makes it less efficient, but also actually runs cooler than a lean ration would because not as much of the fuel ignites due to the lack of air for the amount of fuel you're putting into the cylinders.
This is why electric vehicles with no gearbox and only one bit going round and round makes so much sense from an engineering standpoint.
bzzzt!!! That's the sound of the winding of your cool hipster electruk motar generating an open SOMEWHERE on its winding. Result? SCRAP ENTIRE MOTOR (i.e. motor core labeld BCM and sent to OEM rewinding facility for MAJOR profit for what would be a tiny repair on an I.C.E.). But hey Eron Muskmellon said they were the cool new thing, so how could he possibly be wrong? He's not wrong about ANYTHING, EVAR!
But then you would need a motor for each wheel. Putting in a gearbox allows you to power multiple wheels from only one or two motors.
+Jimbo Jones 2wd Tesla's have no gearbox. No need for one.
+Slappy Fistwad electric cars were far more popular than petrol cars before the oil companies learned how to market
ArchimedeanEye 2wd Teslas do have a gearbox. It is right next to the motor. Go to a showroom that has a bare chassis on display and you will see it. 4wd Teslas have two gearboxes.
Is there a rough guide on what is the minimum RPM required to floor it at a specific speed?
Older cars you can floor it with no probs...
Not true. While compression might be lesa high, the quality of the parts may also be worst. At that point im talking really really old cars
Thank you Jason for sharing and educating us car enthusiasts!
Do this apply to turbo charged diesel engines?
Poor pickup trucks, they are lugged their entire lives.
unless they are diesels in that case they live in low rpms so lugging a diesel is nearly impossible as someone else In this comment section said
wut? You can only lug a manual transmission, and it's becoming harder to find any truck with a manual. Automatics will always change the gear when you hit the gas.
my auto 4.2 lugs if I half throttle it
Wow man you really put the best information on this platform. Your channel is certainly the most helpful to determine which truck I'll buy. Thanks so much.
I was actually using this 'technique' ( high gear, low RPM) to heat up my engine faster, especially now during the winter periods. My 2.2 L. high pressure turbo diesel needs 20 minutes of driving to start heating up normally in urban/ high traffic environments, however if I put it on 4th or 5th gear with 1400 rpm and push the gas pedal it starts heating up much more faster and the turbo works harder to compensate... And believe me, when outside is -17 degrees Celsius, you really want the car to heat up faster... haha
+Tsetso Zdravkov as far as lugging your engine, it's always a bad idea for gasoline engines as it can lead to pre-detonation; especially bad idea when the engine is cold. I certainly wouldn't recommend for diesel engines either, but since ignition is based on when fuel is injected, you likely don't need to worry about knock.
I just can't think of any other way to heat it up faster... maybe the old east-european technique with putting up a piece of carton in front of the radiator could also do the job... But this is a nasty type of solution. Those diesels were not meant to be driven during the cold winters.
As for the carton, you can find and laugh at the example here: www.4tuning.ro/images/halloween-auto-made-in-rusia/halloween-auto-made-in-rusia-c470a1b32746075d6f-0-0-0-0-0.jpg : ))
LOL, I did the same with my moms old car in the winter. Of course I used the block heater before starting, but a 1.8l carb Camry does really not heat up quick. If the engine would have blown up mom would be 500€ poorer, as that is what the car was sold for in the end :)
Tsetso Zdravkov a
go get a heat pump. it warms the coolant well plugged in overnight so that your motor has some warmth when you first start. it does a much better job then a simple block heater, If your -17 I would also be using your block heater as well
Lugging means higher internal peak temperatures in the cylinder. You could also burn an exhaust valve. Automatic transmissions are a good thing, especially when there are so many people driving around who have no clue about how their driving habits affect their vehicle.
What a rubbish! High or full throttle is close to the best efficiency at all RPM. Every specific fuel consuption diagramm shows that. And it doesn't heat up as much at lower RPM than at higher.
The efficiency peaks at about 1/2 of max RPM. But If you don't need the power it's always more efficient to have much or full throttle at lower RPM than less throttle on higher RPM, cause efficiency drops with throttle (lower than appr. 90%).
And to prevent knocking there's motor management, that sets ignition timing right. You are talking about engine technology from the 1960s, Sir. And lower speed of gases inside the engine is always better for homogenous distribution and so for even combustion.
I had so many questions about this on the "things you shouldn't do in turbo vehicles" and sadly none of them were answered here...
1. What specifically is considered lugging an engine? Is flooring it at 2k rpm lugging? 2.5k? 3k? I realize that number will vary engine to engine, but just a general rpm would be nice.
2. I assume you don't need to worry about this with diesels, as they kind of operate via pre-ignition anyways, but it's worth addressing anyways.
3. What about engines that run at inherently low rpms? Most vehicles made before WW1 couldn't even rev above 2k rpm!
Yo dude, you are getting grey hairs. Too much thinking?
that's rude scumbag
I'm cursed as well. Going to be all Grey at 30
ayy lmao Aww, did I trigger you?
@ England imc Whatever, Daisy...lighten up
It's called... the Rich man's look! 🤑💸💰💲💵
I would like to add that GM found that engine oils with a high content of calcium may also cause LSPI...so use low Calcium oils that have some of the calcium replaced by other additives
How you gonna roll coal if you don't lug your engine? Murica' :)
Mike Gresham rolling coal is gay
Ive changed the way I drive my car because of your videos! Thanks for the education!
Another reason why you should buy an electric car.
Haha 😂
electric cars are awesome
+Jason Rochester that's cute
yea if you want to look 'Mas Puto'
Nice presentation, but I think the explanation about oil dilution missed the mark.
Blowby will cause gasoline to mix with the oil in the sump. This mixing causes some of the lighter components of the oil to evaporate and go through the PCV system back to the intake manifold. So essentially the dilution increases the amount of oil droplets in the intake air stream. (It also causes intake valve deposits, which are a problem with direct injection engines.) One way to mitigate the problem is to use a low volatility oil (low NOACK number), like a synthetic, which has less lighter components and hence reduces the susceptibility to evaporation when mixed with gasoline.
I'm not an expert in this, but I read some information about intake valve deposits that had this as an explanation.
What a load of crap. Any modern engine management system worth its salt avoids all of this.
this only applies to manual transmissions
Not all of us drive modern cars, now do we?
TwilightTheShooter That's certainly true. But by modern I mean anything past 1990. Which is the vast majority of cars on the road. This video also seemed for focus on modern vehicles.
TheProPilot well since you cant drive it has nothing to do with you...its for the other half of the population, that can drive, and would get 600k out of a toyota motor...you may as well just buy a nice comfy dodge to wrap around telephone pole
Not crap at all. I drive an STI and there are plenty of clowns who destroy some part of the short block this way. The wastegate on the stock turbo is too small to accommodate a catlesss system even with stock injectors. In this case, there are hardware limitations that the software can't resolve. It's kind of funny actually. The turbine is small enough to allow overboost at low RPM, and again too small to relieve back pressure if you're trying to pass 120 mph.
That being said, there are ways to program discrete ECU maps per gear, but I'm about 99.9999% sure that requires a 3rd party ECU. A lot of Supra owners actually do this so they won't spin their tires through the first 3.5 gears in drag races.
There should be a curve with throttle position and RPM on the X and Y axis, which tells which combination of RPM and throttle position would qualify as lugging. Because for the same RPM, some throttle position might not be lugging at all, while some higher RPM might clearly be lugging.
On the other hand, if you downshift, your engine rpm will increase which will lead to increase in friction in the engine which in turn will make the temperature rise and make parts wear faster, so yeah i think its safer to lug the engine, thanks for nothing.
Maybe. Are you? Guess i´ll take one of those fun and totally accurate IQ tests to find out
I'll give you an example. In my teg I drive in 4th gear at 60 km/h with 2k rpm. The best thing to
Do in this scenario is to downshift into 3rd if my speed starts to drop under 60km/h and then shift back into 4th if I'm trying to accelerate past 60. By shifting from 4th to 3rd going 55 km/h my rpms will go from 1.8k to about 2.8k rpm. The car drives best when it is at 2 k to 3.5 k rpms. So by downshifting it would put me in the optimal Rev range of the engine to give me the boost that I need, without having to lug the engine.
Depends what kind of load you're putting on the engine. Heavy? Put more gear in it.