Torque Is NOT How Far You Move The Wall
HTML-код
- Опубликовано: 17 фев 2018
- "Horsepower is how fast you hit the wall, torque is how far you move the wall."
Horsepower vs Torque (Actually Explained) - • Horsepower vs Torque -...
EE Shirts! - bit.ly/2BHsiuo
Recommended Books & Car Products - amzn.to/2BrekJm
Subscribe for new videos every Wednesday! - goo.gl/VZstk7
If you've ever tried to understand the difference between horsepower and torque, you've likely come across this silly expression: "Horsepower is how fast you hit the wall, torque is how far you take the wall with you." And while I created a video without the use of bad analogies to explain the difference between the power and torque ( • Horsepower vs Torque -... ), the comments were flooded with the inaccurate meme anyways.
Unfortunately horsepower and torque shouldn't be oversimplified to a short analogy, even if neither of them are all that difficult to understand individually. In this video we'll analyze the expression, and discuss exactly why it is inaccurate, what a more accurate analogy would be, and hopefully clear up additional misconceptions about power and torque through the use of dyno plots and a comparison between a diesel engine with lots of torque, versus a gasoline engine with not much power.
Engineering Explained is a participant in the Amazon Influencer Program.
Don't forget to check out my other pages below!
Facebook: / engineeringexplained
Official Website: www.howdoesacarwork.com
Twitter: / jasonfenske13
Instagram: / engineeringexplained
Car Throttle: www.carthrottle.com/user/engi...
Amazon: www.amazon.com/shop/engineeri...
EE Extra: / @engineeringexplainede...
NEW VIDEO EVERY WEDNESDAY! 
Авто/Мото
![BETA SQUAD vs AMP FOOTBALL MATCH [OFFICIAL STREAM]](http://i.ytimg.com/vi/ChEmvP52p0U/mqdefault.jpg)
Hello everyone! When I made my latest video on Horsepower vs Torque (ruclips.net/video/u-MH4sf5xkY/видео.html) I specifically chose not to use any analogies because I don't think they accurately help you understand the two different concepts. To my surprise, the comments section were still filled with the analogy mentioned in this video. There were also a lot of questions about towing, so I've included a comparison at the end of this video demonstrating the difference between a good power-to-weight ratio and a good torque-to-weight ratio. Thanks for watching, and have a wonderful day!
Instagram: instagram.com/engineeringexplained/
T-Shirts: bit.ly/2BHsiuo
Engineering Explained sounds like you have made, or need to make, a better analogy, so you can make a better shirt!
You're just great Silver liner 👌👌👌👍👍👍
Engineering Explained Should have made your analogy "Horsepower is how fast you hit the wall, and Torque*RPM=Horsepower"
I would totally buy a revised t-shirt concept, if you were to sell one...
Terrific video (as usual). Just add that the reason why torque is important in a truck is that the maximum towing weigh depends on it. I thought that it where you were going with the S2000 vs F250. What's interesting there is comparing their maximum towing weights and how it is a function of torque and not power.
Keep it coming!
I'm not taking motoring advice from people that keep hitting walls.
Redoralive lmfao
Or garages...
😂😂
Can you make some shirts with this whole dialogue on it? I want to be accurate when wearing my car shirts.
😂😂
S200 owner right here ! 😁
F25 owner here!
Ahah i wish i was that Rich ! And i also wish i had an s2k...
Engineering Explained
No seriously , if someone wants to read it why not offer a built in lanyard with a magnifying glass on it so others can read it?
"Horsepower is how fast you hit the wall. The wall is why you have brakes and a steering wheel"
"nah dude, science"
-engineering explained (2018)
Horsepower is how fast you hit the wall. Accumulated kinetic energy divided by structural integrity equals how much shorter the vehicle becomes after running into a wall.
Ok, yes basically more power equals more speed, true. But then how far you move the wall? What does that suppose to mean?
@@inox1ck This analogy is incorrect because it relates force with momentum which is completely wrong because momentum = speed * mass so you could just hit the wall harder and move it farther by just increasing your mass but remaining at a constant speed and vice versa. Lets assume a tractor/car is stationary against a wall and it has infinite grip (so the wheels dont spin) and you have a really high torque low horsepower steam engine, you will be capable of pushing the wall with immense force but at a slow rate because of its low rpm thus why it has low hp figures (horsepower is a measure of how much work can be done in a certain time frame). Hope this clears it up somewhat.
torque is how hard you hit the wall
@@its_robbietime1333 this is still wrong. it's still related to horsepower
@@larrythemanic6.0mechanic78 A engine with a light flywheel stalls easy, but has a lot of power somehow.
Warning Mustang Joke
Hp is how fast you hit the crowd and torque is how far you drag the bodies
sam I cried😂
i gave you an upvote and i drive a 95 gt xD
Hahaha drive a 98 gt and still love mustang jokes
torque is how many bodies you can drag at once
Nah dude science
This is the mechanical equivalent to "It's not the voltage that kills you, it's the amps"
"Nah, dude, science!"
Stupidity is how fast you hit the wall, bravery is how far you move the wall.
hugodabos common sense is driving away from the wall
Stupidity is hitting the wall, the speed at which you hit it determins how far you moved it.
theravedaddy if you have enough weight to move it. If not, deceleration is endless😀
In soviet russia, wall move you
@@dosmastrify *our* hero
@@iampurechaos yeah the hero comment is gone
@@mayankraj2294 lol ok
@@iampurechaos what was it if you don't mind me asking......
@@mayankraj2294 i think it said "my hero" or "our hero" or something like that
im honestly amazed i remember it after a year
God thank you, the arm chair engineers on social media drive me crazy with this one!
acceleration depends on torque, but torque is also a function of engine power and rpm.
acceleration = (Wheel Torque)/((Wheel Radius)*(vehicle mass))
Wheel Torque = (Engine Torque)*(Transmission Gear Ratio)*(Rear end gear ratio)
Engine Torque = (Engine Power)/(angular velocity)
Just make sure you use consistent units, and "wheel radius" included the tire height (distance from axle centerline to the ground).
I know the feeling. I had a knock-down, drag-out argument with someone on the old SPEED TV channel about the difference between torque and horsepower. I explained what each one was, I showed him the equations, I "did the math" to demonstrate how engines of "similar horsepower" could have radically different torque, gave him examples of different vehicles with "similar" numbers and so on. He still didn't understand.
38 seconds in and this is immediately in my top 5 all time favorite RUclips videos
Jared C good thing youtube doesn't have porn
Alex Gunner well if you dig far enough....
The most important thing to remember is that torque and power are inter-related. Although, power is a more comprehensive indicator of how fast a car will be
Horsepower is how many bricks you can lift per minute
Torque is how many bricks you can lift at once
That's actually seems like a real good analogy
Dude this is perfect.
You could change that to groceries to make it even more relatable so people can understand it even easier.
"Give me a place to stand and with a lever I will move the whole world."
It's not about how many bricks you can lift.
put that on a t-shirt, wont be long before you see a vid on youtube called 'Torque is NOT how many bricks you can lift at once!'
actually no, how many bricks you can lift at once is still a unit of energy, which tq is not
All that matters is the power curve. When people say a certain vehicle has "a lot of torque", usually what that means is that that particular vehicle has an early (rpm-wise) power delivery and/or a more broad (as opposed to peaky) power curve. Both of these characteristics can be very useful depending on the situation.
Another key detail that someone may have already mentioned regarding towing, is that with a high torque vehicle, the power band is such that you can make enough power to tow while staying at a comfortable RPM. Say in your F-250 and S2000 example that the BHP/lbm and lb-ft/lbm ratios stayed the same, but the weights were equal to one another, the F-250 would still likely be the preferred towing vehicle because you wouldn't need the engine to be milling at ~5000 rpm in order to comfortably tow your boat on the highway.
government said "let there be schools" and internet says "let there be engineering explained!". thank you for clarifying all these information man.
When you get so triggered by a T shirt logo you hunker down, break out the science and lecture the internet.
Right? I didn’t even need to watch the video.
He's an engineer. With a RUclips channel called "Engineering Explained." You have to assume that explaining engineering is kind of his thing.
We found the old v8 guy lol
Thank God that it's these "triggered" engineers who build your motorcycles. But hey, if you want your education to come from mugs and t-shirts - have at it!
i don't know dude this comment comes across pretty passive aggressive. its okay to be wrong, learn from your mistakes, don't be that guy...
The way yo explain things is sublime, I'm forever grateful that I found this channel. Keep it up!
Thanks for watching!
I have made that grave mistake of missing out analogy not at all questioning it and I'm really glad you explained it and set the record straight! Thank you!
I've a favourite playlist, but it's now under the subscription bar named Engineering Explained. Great video Jason
I haven't made the effort to comment before, simply because I go on to your next vid as quickly as possible.
Absolutely top rate & professional vids my friend.
All of your vids do yourself & viewers nothing but a service.
Please keep up the excellent work.
your channels is great , i enjoy the physics calculations and objective analysis
Will you make a video on why Diesel engines have a ludicrous amount of torque and can’t rev very high?
Indeed I will!
Good idea!
Basically because diesels have a longer stroke to create higher compression ratios to combust diesel fuels. And since the stroke is longer the crank “throw” is longer. Which gives the crank greater torque or “leverage” to produce work. But since the piston has to travel so far up and down it cannot do it as quickly as a shorter stroke gasoline engine.
Evan Williams, there’s some high stroke high rpm motors, I think the 10,000 RPM K24s that people build have a stroke close to 100mm that means piston speeds are super high. As far as I know it’s just due to the slower burn rate of the diesel fuel compared to gasoline.
I think he did explain . IIRC diesel needs high compression ratio , using same bore of cylinder that is achieved with longer stroke , the piston moves down further than a similar bored gas engine. Torque is function of force x distance , so longer stroke = longer distance , hence more torque. Lower revs is due to heavier components to generate the high compression safely, heavier block , cranks, piston hence physically limiting the max speed it can rotate to. Except for the skyactiv diesel with lowest compression ratio in the world for diesel at 14:1, all aluminium block and revs to 5200
Then there's Carol Shelby who said "horsepower sells cars, but torque wins races". 'Splain that one, Jason!
Now tell people at any given rpm the same torque equals to the same hp. And then explaining that torque and hp changes dynamically with the rpm band.
You’ve taught me so much, I’d like to return the favor (to a much lesser degree). You say @ 1:45, “...the further it will move.” It should be “farther” since you’re talking about distance (vs. degree). Thanks for all your vids!!
I have been Dyno testing incorrectly this whole time?! From now on before and after upgrades I'll be doing the wall test! Thanks for the information
The analogy comes from Top Gear, where everything is just basically a joke.
I believe that quote is actually attributed to Carroll Shelby.
It is much older than Top Gear. We've been saying that for a very, very long time. Patw52pb1 is probably correct in attributing it to Caroll Shelby.
It is just a joke trying to explain HP vs torque to the general masses and it honestly is a descriptor of HP in both cases, but it gets the point across well enough to your aunt that doesn't give a crap about this discussion.
You can't measure work with torque, that is done with HP. Both are examples of work. This is just a joke explanation.
@@glenwaldrop8166 torque is work. Hp is rate of work.
@@jdrok5026 torque is force applied.
You can apply 1000 ft lbs of torque on something and never have it move. Prime example, transmission brake, 1000 ft lbs of torque applied to a fixed item producing no work, no horsepower.
The actual definition, torque is force applied, horsepower is work done.
Better example if you can only apply about 100 lbft to a bolt that's torqued to 425lbft what you are telling me is that if you have 500 hp but not enough torque to break that bolt lose that 100 lbft at a rate of work of 500 hp will break it lose just because it has 500 lbft. Well this isnt true. Let's take a look why are impacts rated at torque not hp. Well because if your trying to apply to little force and cant overcome the force being applied against you you arent moving you cant produce any work. So torque is definitely not useless.
Horsepower is how fast you hit the wall, torque is force multiplied by the lever arm length.
I tried requesting this counter weight idea to hoonigan to measure the pull of a burnout. I couldnt put it into text very well but your illustration is the exactly the idea i had in mind.
thanks for helping me finish my physics research project,
because of your explanation in this video and other video
i got full marks on my project...great presentation...
you should expaine how it works with bigger and heavy rims and slower acceleration due to change in final drive gearing loss in wheeltorque and momentum effect on spinning object.
hate hate HATE the talk that bigg heavy rims dont impair on acceleration compared to smaler and lighter rims.
He's talking about power generation not power transfer. 2 totally different problems.
i know it was just a sugestion for another topic.
In theory rim size does not influence acceleration, because the increase in moment of inertia and the decrease of of angular velocity cancel each other out perfectly. SO no rim size does not matter. In practice larger rims are typically heavier and heavier rims will decrease acceleration.
extec101
I would like some in depth look into “weight reduction”.
Static weight removal by taking out unnecessary weight(passenger seat or rear seats) vs reducing rotational mass with lighter wheels, or lighter drive shaft; and which has the greatest effect on performance...
thats a interesting topic and something i thought about too.
How did humans build dams, build pyramids, skyscrapers, go to the moon, but need a RUclips guy to explain basic physics
O K xD
Everybody has to learn something from someone else
maybe they aren't the same humans
So I assume you knew this when you came out your mother's womb?
I've never heard this analogy before, but i have heard the one at the end of your video, "torque is what presses you back in your seat and horsepower is was keeps you there", and I like that one. I definitely noticed it when i went from a turbocharged diesel vw jetta to an NA 5-cyl vw rabbit. the rabbit had more torque and hp outright, but i didn't feel the seat pushing back phenomenom until way higher in the rev-range, whereas with the diesel and turbo you got it a lot earlier....
Love watching your videos man 👍👍👍👍👍👍
torque is what you feel
horsepower is how long you feel it
No. that makes no sense. Horsepower is what you feel. Torque by itself does not tell us much, we need to know RPM where that torque happens (which is horsepower when calculated).
E.g.
When you feel acceleration, you cannot tell is it 300 NM, or 50NM, But you can know if it is 100 HP or 10HP.
Let's say we are accelerating with full throttle in car in same gear:
- 1. Acceleration with engine of 300 NM from 1000 to 2000 RPM is 42HP to 84 HP
- 2. Acceleration with engine of 200 NM from 6000 to 7000 RPM is 168 HP to 196 HP
So second case is what you will will as much stronger pull, even though, it is 100NM less.
It seems like people who believed that horrible analogy had their head hit the wall when they were young.
I am a big fan of your videos. Not just because I am a halfbreed of nerd and car enthusiast but also you are able to explain things to an average halfwit too! :-) Carry on doing what you do and enlight us regularly!
Cheers,
Dan
Excellent vid. Keep up the great work. Really enjoying your channel.
Thanks!
Oh. So that's what spoilers are for
In soviet russia, Horsepower is how fast the wall hit you and torque is how far the wall moves you!
Davin Yap heard this back in 2008
In soviet Russia, the car moves YOU
Shockwave Shockwave wouldn't it be in soviet Russia you move the car? Haha
Davin Yap - In Soviet Russia you never say, "Your mother wears Army boots." Because she probably does. And she will hurt you.
Because it runs on vodka, not gasoline
Jason THANK YOU! as a fellow engineer I always shook my head when I heard this analogy.
THANK YOU SO MUCH! This cleared up so much! Many many years, never got it till now! Thank you very much!
I believe the correct 2nd part would be "Torque is how much distance you need to hit the wall at said speed"
No that's horsepower... He said that at the start of the video.
I have e never heard this analogy. Great video though!
Bill Carini the internet is full of this silly analogy. You are probably lucky you didnt hear it.
Excellent as always...i live for these videos...
I like the videos, keep it up. One comment......I have seen different videos about torque vs horsepower, and no one ever uses tractors to help describe the difference. That is the way I was taught (back when the wheel was invented). Compare a Honda to a John Deere Tractor. Tractors are low in horsepower (although some of the newer ones do have HP in the 100-200 range), but can pull/lift/etc huge amounts of weight, albeit slowly. This is because they have a hell of lot more torque, running at low RPMs. If you plan on doing another video about torque vs horsepower, maybe try comparing a sports car to a tractor. In fact, what would be very interesting is to see how the engine differs between the 2. From what I understand, tractors have huge pistons which gives them the higher torque. While cars have small pistons. Just a thought.
I hate when I hear people say this
Oh, and first
Y'all cant take a joke lol
Hi there. For the F250 vs S2000 comparison (for 0-60), I feel like without equal gear ratios the analogy is lost. I’m assuming that the powerstrokes low revs dictate longer gearing for the purpose of being able to go more than 10mph in each gear, while the 9000+ish RPM of the S2000 allows it to achieve a much higher velocity in the same gear. Would I be right in saying that?
Tl;dr gear ratios play as much of a role in 0-60 as power to weight/power to torque etc.
I’m assuming that if both the S2000 and the F250 were geared in such a way that they hit exactly 60mph in first gear, the S2000 would have a major advantage because it travels across a much greater rev range to get there, but if the S2000 hit 60 in the top of say, third gear, and the truck hit 60 at the top of 2nd, then I would feel the torque of the F250 would give it a slight advantage.
For reference, I’m a simple car enthusiast and college computer science student that took 2 levels of engineering physics, but I am always trying to learn!
As described in the diesel vs gas dyno plot, yes they will have different gearing (hence the initial explanation with the same gearing). To not account for gearing in the real world is silly, as you would never create a gearbox that doesn't match an engine properly. Ford knows what they're doing, as does Honda. Both are optimized for the engine. And fully optimized, power-to-weight is far more important than torque-to-weight, as the comparison demonstrates.
Engineering Explained gotcha. Thanks for the response! I guess my question had more to do with the optimization more than the theoretical stuff. I’m definitely not claiming to be correct, but it just seems to me like the Ford is “optimally” geared for a different application than the S2000.
One is geared for quick spirited driving and the other for heavy-duty towing. I put quotations around optimize to show this.
I’ll do the research myself, but I would like to see a comparison between 2 more similar vehicles, as I feel like that would result in slightly different results. I’m thinking using a BMW 335i and a BMW 335d whenever I look at numbers and stuff.
Once again, thanks for helping clear some of that up!
Ryan Ristau just to clarify - yes, given sub-optimal gear ratios, the race could go either way. A single gear for either vehicle to get it to 60mph might give the truck an advantage, at it likely hits peak power production in a significantly lower percentage of usable RPM range than the S2000. That being said, if both vehicles used a CVT that could hold them at peak horsepower at all times during acceleration, the only metric that determines acceleration is power to weight ratio (ignoring wheel spin, kinetic friction, aero drag, etc)
Greg McNamer that actually makes perfect sense now that I think about it that way
Hey Engineering Explained, I just want to start off by saying thanks for your videos they are immensely informal and interesting to watch. I wasn't sure how to contact you so I'm gonna comment on your latest video. To get to the point I needed to do a project for school and I needed to make a RUclips video on how rotary engines work so I took the main bullets from your 2 rotary engine videos and put it in my own words. So if you stumble upon this video that sounds a lot like yours please don't flag it for at least a month, after that I really could care less. Thanks a ton and please keep making videos.
Thanks, hp/tq finally make sense. I was always confused by all the wrong analogies.
My 22 year old ford explorer has a 0-60 of 15 seconds. :o 3800/160 = 23.75lb/HP
My 8 year old honda insight has a 0-60 of 8 seconds. 2600/106(88 HP engine and 18 HP electric) = 24.53lb/HP
Could that be the difference of manual vs cvt?
On a side note: the numbers I find online for both vehicles has them both at 12 seconds. The ford has slack in the throttle cable but the only time that noticeably affects the driving is in 4th or 5th gear at highway speeds. The honda is plain stock with better tires than stock... not that it could spin the tires in the first place.
Gearing differences, if I had to guess. What are the diff's in the two vehicles?
+Confinium I don't know how to find out for FWD vehicles as they don't have a diff I can look for the tag. The truck is 3.27. 70 mph is 1600-1650 rmp. woohoo. lol
If I had to guess the Honda probably has an advantage due to less drivetrain losses what with not having a giant driveshaft to spin to turn a diff to turn the rear wheels along with transmission/electric motor
acephantom903 also less air drag, a passenger car is pretty much always better than a truck in that regard
+Black70Fastback I know what you mean by engines losing power over time. I believe that the engine is still producing its bhp as the engine is known for being extremely reliable and long lasting at the cost of power (Ford Cologne V6 4.0 OHV -- the SOHC were notorious for camshaft failures) . Other components of the drivetrain have probably not fared so well. I think it is down to the gear ratios of 3rd gear and the rear differential which cause the slow down. 1st gear is tall, 2nd gear is short, 3rd gear is very very tall, 4th is short and 5th is tall and the rear differential is the most fuel efficient of the 8 rear differentials on the explorers in that year which mean loss of power. How I accelerate 0-60 in the explorer is 1st to 4800 RPM (redline 5000) which brings me up to 35ish. Shift straight to 3rd which will now be at 2000 RPM and peak torque is 2800 RMP. Then take 3rd gear the rest of the way. The only point where it would start losing power would be at 4300ish RMP in 3rd but that is 75 mph and above the 0-60 measurement. To keep power past that point, I would have to tighten the throttle cable as it is a quarter inch too long... it is hard to find OEM parts for vehicles this old and I had to make do with what I found from a 2004 vehicle.
I think the reason the honda gets the better time even though it has a worse power to weight is because of the CVT and electric motor mix. 0-10 is 1 second, 10-45 is 2 seconds (I think that is pretty fast for a putt-putt car) then 45-60 is just under 5 seconds... it really doesn't have any power once the electric motor can't keep up.
The main reason I was posting this was to point out the flaw of him comparing a truck and a sports car and using power to weight as the main factor. One is designed to go fast, the other is designed to move weight. Both my vehicles have roughly the same power to weight but they have dramatically different results.
torque: how much twisting force an engine can produce
Right
Also torque like you said it's the work you can do, when you're towing you need to be able to do the work but necessarily able to do it quickly. Also having it in the lower RPM means it will be easier to start moving without putting high stress on components.
I have 99 dakota rt, the redline starts at 4700 rpm. I havent dynoed it but dodge rated it at 250 hp and 350 of torque. It was designed as a truck motor and since they put it in the smaller dakota it moves quicker. Now i can feel that the motor has more power potential in it. When i accelerate i can feel it stop accelerating quicker at around 2500-2700 rpms, it still feels like its going quicker the longer i hold it in that gear but there's obviously restriction. Most likely the intake, exhaust and smaller cam, but for a gas engine i really enjoy it because it holds its torque pretty well and theres no feeling of it dropping off.
I get the concept... kinda... I think. Torque would be how well you could overcome resistance...? Like how large of a wall could you push from a standstill?
Best way is to move aside from vehicles (because gearing causes a lot of complexity) and think of something with human power vs object. For instance, moving heavy furniture. A sub 3 hour marathon runner will struggle to even budge a piano (without wheels on it) because he does not have the torque needed, i.e. his legs are tuned to be moving at high cadence (rpm) with minimal upper body strength to keep trim. However, a big burly fat guy will have huge amounts of low end torque to get that piano moving in relative ease. In this example, the marathon runner is the S2000 and the fat guy an F250. If you lack sufficient torque, you aren't even going to budge the object you are trying to move.
It's kind of irrelevant because you can easily manipulate torque through gearing. You can't change power through gearing though.
hp: how fast the engine is capable of delivering that torque to load
acually, right
One of the many reasons why I love this channel.
Fantastic explanation as usual
Awesome video, EE! But then it got me wondering - if horsepower is all that matters to determine how fast a car is, why do racing games and car enthusiasts look at the torque figures?
The torque curve is important, especially for geared transmissions which go through the rev-range. The higher and flatter the torque curve, the better (and the more power you make).
Engineering Explained I see.. that makes sense. Thanks for replying! 😲😁
Torque curve comparisons are most useful when it's being done on the same car... i.e. gearing is the same. After all, you can add horsepower to a car, but if you've sacrificed torque everywhere else in the rpm range to get that bump in the last 1000 rpms, you'll have a slower car. In order for HP to be "relevant", the gearing needs to be changed accordingly.
TruCkADDiCtiOn kinda wrong.
Drifter D Torque is your low end power
In Soviet Russia wall moves you
Duck how is this not the highest rated comment 😂. The car does 30 hectres on a single tank of kerosene
Thanks for the video. Best channel on RUclips!
Great video. I learned something new and important : horse power to weight ratio. Nice point to take into account on cars
For those of you who measure a cars power in KW then this video is not for you.
Thankfully, people usually use kW for that. Doesn't really have that much to do with temperature. :)
Temperature?! lol
But in seriosity, kW is what's in the motor windings, not what's on the wheels.
And BION kW and HP fundamentally measure the same thing.
A big 'K' is Kelvin, buddy.
Why not? kW is just HPx0.7457.
qwesx Well he obviously did not mean temperature
Nah dude science. 😂.......💀
Just used that on a drag racing vid
SCIENCE!!!! Thank you! Over here (UK) we have comparably powerful diesel and petrol cars in the same product ranges, with wildly different peak torque figures, I can vouch for the fact that any given 2-tonne car with comparable torque curves and optimal gearing will accelerate at a similar rate regardless of whether they have a high-revving petrol engine or a low-lugging diesel engine.
What you didn't touch on was the fact that the S2000 in your example has a very peaky torque curve but the turbo-diesel, by virtue of the turbochargers, has a very flat one so you need to take into account the area under the curve (calculus ftw) but I love your videos so much it doesn't matter :-)
I'm just so glad that someone has finally addressed the point that you can't just arbitrarily say "MORE TORQUES EQUALS MORE BIGGER CRASHES INTO THE WALL DURP!!!".
I have a 2000 Lexus RX300 AWD 3. Liter VVTI with a curb weight of 3692 lbs, 220 HP @5800 RPM, and 222 ft lb. torque @4400 RPM. It is a 4 speed transmission. It has 3500 lb towing capacity. I tow a 2700 lb travel trailer. I know people will say I am crazy to be towing anything with this car but it is what I have and have been successfully towing up and down hill for about 15,000 miles now. I've also added an external transmission cooler which I average about 175F to 215F. I also have a weight distribution / anti sway bar. Based on your video, I have 16.8 lb/HP and 16.6/ lb-ft. When the trailer weight is added, I have 29 lb/HP and 28.8/lb-ft. I tow with overdrive off which is the 3rd gear at 55 to 60 MPH at about 3000 to 3500 RPM. On a very steep hill, I need to drop to 2nd gear and at around 4600 RPM at 50 to 55 MPH. The car redline at 6,250 RPM. I feel uncomfortable driving the engine between 4000 to 5500 RPM.
Questions: 1. Should I not be driving the engine close to its peak HP and torque?
2. Or is this high compression engine designed to be driven at high RPM range without hurting anything as long as the temperature gauge is within normal range?
3. Would you recommend using 91 octane under heavy load? Owner's manual,says 91 recommended for improved engine performance but 87 is required.
Thank you for your great channel! @Engineering Explained
So, when electric car enthusiasts brag about peak torque at zero rpm, that means they are producing zero horsepower at the peak of their torque curve.
Andrew Whiteman yep, but you still need to get moving... which takes torque.
Electric motors are beautiful because they produce full torque (full current) up to the electrical voltage and phase timing limits, which means they will have more horsepower at any given point than an IC engine of the same torque, up to this limit.
All bets go off above this point in regards to torque.
Andrew Whiteman There's electric car enthusiasts?? Oh boy...
RPM? Is it relevant to an electric vehicle?
@@juansiahaan6698 yes rpm is relevant. People generalize dc. As ac dont produce full torque at 0 rpm much like a dc doesn't but at the starting speed of the dc motor it does create its max available torque. Ac however dont until they are in phase.
RPM=amperage, torque=Voltage, Hours Power=Watts
thats cute if you understand electricity which most people dont
Mike Shea well... wait...
I wanted to correct you but... that is pretty correct, even engine power is measured in watts
True, but you've got it backwards. Voltage equals RPM, amperage equals torque.
High torque requires a large shaft, high amperage requires a large cable. Voltage is easy to measure without breaking a circuit, so is rpm. Both voltage and RPM can exist in a system doing no work, amperage and torque are created as a result of that system being put under load (there are exceptions).
Think about an engine driving a DC generator. Under no load, voltage will be proportional to speed and torque will be zero (plus a little from windage and friction loads). Put a load on it and the voltage and rpm will drop a little but the torque and amperage will go way up.
bhartley1024 yes but a high amperage requires a high voltage to be sent through a higher resistance circuit, as RPM needs high torque to be achieved in an environment that puts resistance on the shaft
Hmmm.... well electrical and mechanical measures can’t really be compared as they have different characteristics.
I agree with bhartley, torque is amperage, RPM is voltage.
Great Video
Thank you soo much Jason 👍🏻👏🏻
Hey there. It’s me again. I wrote this analogy in the previous torque HP video as a joke. I really loved the explanation and actually understood the concepts from the previous video. Apologies for any confusion caused, I only meant it as a joke referencing Jeremy Clarkson (I think).
Still wrong... Torque is how hard you push the wall and horsepower is how fast you can push the wall but to push the wall you need torque so horsepower is still dependent on torque
No you’re wrong, torque is literally force x distance (a twisting force). Hp is how fast you can apply that force per unit of time. Hp is a function of torque because all you’re calculating is how much torque you put down throughout your rev range. This is the formula to calculate hp: (Torque * rpm)/5252. I can create 1000 lb ft of torque if I had a long enough wrench. But I can’t apply that much force quickly enough to generate any useful power. If your assumption is that torque is what is useful for towing then you’re also wrong. Hp+weight of the vehicle is what determines towing capacity NOT TORQUE.
@@megashocker333 but a engine when reading on a dyno is constantly building torque. Because force is mass and speed related.
jdr ok No it doesn’t, torque (when in units of lb•ft) drops off at 5252 rpm while hp keeps climbing. Again this is based on torque being measured in lb•ft, if measured in newton meters it would drop off elsewhere in the rev range.
The one thing i don't get about torque is why you measure it in pound-feet.
What do british currency and body parts have to do with it?
Shouldn't it be measured in Newton-Meters instead?
Just an american thing.
International standart is N*m
cgs is dyn*cm
Just remember that England held sway over the world economy for a century-and-a-half with that same quirky agrarian-based measurement system.
"Logic and knowledge, are not enough."
-Spock
Hannes Größlinger We tried that in America- It didn't take- you can blame our government
Because England is weird... But not weirder than the united states of freedom
So annoying... why not use nm. Americans wont understand it neither you use pf or nm.
Adjusting the torque is basically trading acceleration for speed. High torque = high acceleration but slow speed. Low torque = low acceleration but high speed. That is what the gears do for an engine. The engine produces the same power for the same revs regardless of the gear you are in.
great video as always all this talk about torque and horsepower made me thinking about electric starter motors. Because they have amazing amounts of torque like all electric motors. My question is about why do we even need electric starter motors in gasoline engines? This might be a good idea for a video maybe not. But I was wondering what part of the design of the internal combustion engine makes the electric starter motor crucial for starting the engine? Why do we have to spin the engine to start it? I'm assuming there is a variety of reasons. But how cool would it be for an gasoline engine do have no starter , it would just start burning fuel and spinning the pistons.
the most obvious reasons I could think of why this wont work is because the fuel isn't in a vacuum unless the engine spins and no oxygen is being sucked in.
Never heard any of those analogies growing up, how accurate is this one. Horsepower top speed, torque is how fast you get there.
Torque is irrelevant when you have gears. It's all about the horsepower. (The shape of the torque curve is extremely important though, only the value is useless)
Torque gets you off the line, horsepower wins races.
Is "Torque is how big a wall you can move" OK ?
No, it's still just mass and power....
Bhavin Tolia no!!!
I disagree with the other comments. Given a fixed gear ratio, yes. Torque determines *if* you can move the wall. Given an unlimited gear reduction, any input can move any mass... It just might be unfathomably slow.
Greg McNamer you are right but given a fixed speed HORSEPOWER determines how big a wall you can move
Bhavin Tolia
To me, that makes sense. Take a John Deere 7920 4wd tractor... 171 hp (wimpy right) but it has 654 ft lbs of torque at 1100 rpms... so yes gear ratio and all that stuff matters and NO I don't really 'get it' all but this tractor would be considered a real wimp in the world of horsepower but could pull that Ford pkup, that little car and a few other pkups all tied together at the same time. I know. I'm a farmer (with several diff tractors)
Never heard that 'wall' quote. In my layman speak, I've always used this: Horsepower is power at high RPM, such as passing. Torque is power at low RPM, such as a stop light. Another one I've heard is "You buy horsepower....you drive torque."
Horsepower is “work accomplished”, power is power there’s nothing else to say about it... all torque is, is the rotational twisting force and horsepower is how efficient that twisting force is working... more torque means a broader horsepower power curve, which is more work over a larger rpm range...
Hello Sir, thanks for this video, especially those useful calculations. If I may, could a draft horse VS race horse comparison be of some use when explaining torque and speed?
To be honest i think you misunderstood the Wall analogy, i think the reasoning behind that saying is in the implication that the car did not simply crashed against the Wall, but actually towed the Wall.
Luis Morais that’s what I thought. Torque is how far a car can push the wall from a stop, instead of crashing into the wall
Slice it up any way you like, torque is not how far you tow the wall either. And the implication certainly seems clear, otherwise it would be "how far you tow the wall."
The problem with the hp vs torque analogy is that they describe hp as it is, but when they say torque, they actually mean high torque at low rpm which results in higher hp at low rpm. In the end, they are comparing two vehicles - one with more hp at low rpm and one with more hp at high rpm.
The saying relates to if you hit the wall and keeping the throttle pinned... So a higher BHP engine but low torque would be less likely to try and keep going. The mass of the car is not what people are talking about. High power low torque engines need RPM to keep going so apply resistance (Wall or big hill) the engine will lose RPM and slow down more than a high torque lower RPM engine in the same situation. So from the analogy point of view it is correct. Hit the wall the high torque engine will try and keep going forward where the low torque engine will struggle. So the pedantry of mass and speed is OK IF the car only hits the wall and the engine is not still running and trying to keep going....
I built a bike to break a lap record and used a 600cc engine not a 1000cc one. To match the larger bikes power to weight ratio was important but so was lower torque and higher RPM as the larger capacity engine made it almost impossible to accelerate hard at full lean angle mid corner as the torque would try and spin up the rear tyre and break traction. The 16,000 rpm redline we had allowed us to open the throttle harder and earlier in the corner.. So it was more horsepower was how fast we accelerated down the straight and Torque was how far the rider would be thrown into the next county.
So its how the engine works with the engine still running and wide open throttle not just hitting a wall....
But your point with the 5000lbs proves this point actually. If you tow the wall, or push for that matter, you need more torque to take the wall with you further. More torque=push the wall further. Right?
Good video, but I've usually heard this analogy used as a joke or an extreme over simplification....
The problem is, some don't think it's a joke or an over-simplification. They toss it out as a casual fact.
As always this was really informative.
Excellent video explaining the concept of Force. Now about the present analogy.........
For a channel about physics, it really bothers me how you chose to draw the pulley^^^,
It's a trick. It's clear that the S2000 would never be able to even pull the weight because it would pull the back axle upwards and leave the wheels spinning in the air.
Oh gee, this is what you are hung up on. It wasn’t a serious comment about towing with a spoiler.
Ty for the video, but I think these 2 physical concepts are really easy to understand.If somebody can't get it it's better not to deal with mechanical devices at all.
You shouldn't discourage people from learning. We all start somewhere. It's better to be helpful than degrading. I made a video to simply understand each concept: ruclips.net/video/u-MH4sf5xkY/видео.html
Sure. All I want to say is that nowadays peolple are lazy, they even don't want to ready some textbooks and figure it out by themselves, as it is an important part of education. At one point there will be no more videous about things they want to understand. But anyway thank you for your great contribution.
Semion Polonsky if someone learns from a video instead of a book, why does that matter?
Excellent explanation
Love the vid EE but I always tell people to study the math if you really want to understand HP and Torque. It wasn't until I did that what things really clicked for me.
You however explain things better than about 99 percent of folks that I know of so keep it up. ;)
Noti squad
Anthony Colon I feel like RUclips should make special tags for the notification squad.
Notification squad 😍
Man...I wish you were my physics study partner back in the day. Great job in illustrating this concept!
Great video! Another issue that confuses people is the velocity at which two cars have at a head on collision. Most commonly said that the collision takes place at the sum of the speeds of the two cars. I believe tit o be an interesting subject
Coment 7?
I wish he would have finished the video. Show how the ratio changes when the 5,000 lbs is added. Then do the torque/horsepower graph again and show how the Ford now accelerates faster than the Honda when they are both towing.
Thx for the great explaination :D
Nicely done!
Man Jason I wish you were my physics teacher back in high school, I would've actually learned something. Excellent tutorial!
"Nineee "Hondred" Twenty Five pound feet of torque".. You are just so good at explaining stuff.
Not to be that stereotypical RUclips nitpicker, but power to weight ratio is hp/lb - higher is better. Power loading is lb/hp - lower is better.
But everyone makes the same mistake, all the magazines say "power to weight ratio" and then publish power loading numbers.
Anyway, keep making great videos! Love the content.
100% agree with you Jason, but i think the saying: "Horsepower is how fast you hit the wall, torque is how far you move the wall." makes sense if you read it like a story: "I used my horsepower to hit a wall, but used my torque to carry the broken pieces of the wall with me." I think this analogy tries to convey the difference between horsepower and torque. horsepower = speed, torque = towing/carrying capacity. fin
This story doesn't make sense. Where are you going after a car accident that destroys a wall if not the hospital? Why would you even take the wall with you?