Hot air is less dense, requires more boost to produce power, which requires more fuel. Same thing at elevation. Not surprising fuel economy dropped in hot temps.
I make that trip between SACC pretty regularly in a 6" lifted F-150 Platinum with the 5.0. I always get considerably better mileage from SA->CC, than I get from CC->SA. I always thought the elevation was the cause of it for me, since I usually make that drive in the heat of the day both ways. With the V8, lift, and bigger AT tires, I get around 16 mpg from SA->CC and 14.5-15mpg from CC->SA.
I drove from Pa to Cocoa Beach on July 7th. When I left I was getting 14.8 with 20x10 -24 offset and by the time I got to cocoa I was getting 16.3. On the way home I got 16.8. I have the 5.0 also with a level kit!! If I used my stock wheels and tires I could have got around 22mpg I’m guessing!!😎💪🇺🇸
Corpus to SA and back is not the best test, it's uphill most of the way to SA and the prevailing wind is a headwind on the way back to CC. SA to Dallas would be a better one.
Corpus Christi elevation is pretty much 0 at sea level. San Antonio elevation is 660 ft. There's your answer.... climbing to San Antonio going down hill to Corpus Christi.
660’ in 145 miles driving distance is pretty insignificant elevation gain and should not increase the workload on the engine at all - wind maybe more of a factor
What cabin temperature have you set with the high outside temperatures being as high as they’ve been. The Air conditioner unit will mess up your mileage. I’ve noticed my MPG have dropped off a bit this summer.
I haven't had a milage change in my baby deisel yet. But, I did just got her back from the dealer after three weeks of waiting. She had an ECU / Emissions issue. Let us know if you experience the same. I'm just over 9500 on my 2022.
That’s a lot of miles for a break In period Oil change I always change the oil before 3000 miles the first time, my 2002 durmax still runs strong with many miles. Regardless of what the dealer says. It’s only 7 quarts and easy to do. My $.02
At 79-80 mph this is what I would expect on a hot day with a 6000 lb vehicle, not knowing the wind direction I’d say it’s within regular operating economy, 80 mph is very fast in my world
The quality of diesel can also make a difference in your mileage also I have learned modern diesels are very sensitive to the quality and condition of the fuel filters
I have a 2022 Chevy RST with the baby Duramax and love it. Super smooth and quiet. Have about 28K miles on it so far with several long trips (Montana 2x, Florida 1x, Michigan to NY 4x). My best range and mileage for an *entire tank of gas* was 660 miles and 28mpg. It will do 50 mile stretches averaging 32+ mpg easy. The two biggest MPG killers are wind resistance and elevation change. JDs experience here is pretty consistent with mine - set the cruise on 80mph and it will get you 24mpg all day. But slow down to get peak MPG. All things being equal, on the open highway, for every 2 MPH slower I drive, my MPG will go up by 1. Headwinds and cross-breezes can be challenging, though - still driving a giant metal box! Other factors that hurt MPG: road surface, temperature, quality of diesel (winter mix vs. summer mix) and tires. It regens every ~500 miles but the MPG drops for about 15 mins then roars back. Interestingly, I've done most of my best mileage when the truck is loaded right up. Towing is obviously a different story but still great by comparison. Pulling a 4000lb box trailer around town and a little highway mixed in, I average 17-18 mpg. The truck is just so capable.
@@nathanielwashington9775 I never know for sure, but there might be a slight increase in engine temps or I might smell it a bit, but the most reliable indicator is the drop in avg MPGs. Example: my 25 mile average might drop from 28 to 22 for about 15 mins, then it will creep back up for the next 20 mins. On long road trips, it tends to happen around every 500 miles and soon after a fill-up. I wish there was an indicator on the display that lit up when it was in regen.
Love your videos, but you can’t drive a shoe box 80mph and complain about mpg. I’m willing to bet my 6.2 that if you drove 2 mph under the speed limit, say 68, you would have gained 3-5mpg.
@@ML-lg4ky yes i think 2018 or 2019 only. I only found this out after I bought a 2020 a few months ago. I shouldve looked for the diesel(YES IN THE US)
On my 2024 ZR2 with 3.0 wind speed and direction is biggest factor. On calm days I don’t see much difference between 85 and over 100F. It is 35% better than my 6.2L 2023 ZR2
Air density is affected by temperature, but also by humidity...gas turbines use inlet fogging to increase humidity and cool air inlet to the compressor. Higher humidity equals Higher mass air flow, cooler temperatures equals more efficient compression.
I'd like to see a Powerboost do the same trip at the same time to compare MPG's. Everyone says the GM seats aren't particularly comfortable, and that is a deal breaker IMO, even with great MPG's.
Check out the ram ecodiesle I have the 10th anniversary edition with the air ride suspension and fully decked out interior. Do a side by side and drive. Think you really can’t beat either of those trucks. Mileage on fuel is amazing.
I agree the seats are not as comfortable on long trips. I filled up in NC with a range of 696 mi! I traveled 576 miles to TN, 31.7 mpg and average speed 62 mph. I set my cruise to 73 mph. I have a little over 10K miles and the fuel economy is getting better and better!
JD, did the truck perform a regen cycle during your trip ? A regen cycle will consume ALOT of fuel and drastically lower fuel economy. The ultra low sulfur diesel fuel we have access to nowadays is simply trash. Im in the railroad business and we’ve totally abandoned diesel 3/4 and 1 ton trucks. Very problematic in winter time during idling situations. DPF would always get clogged therefore causing the trucks to go into regen cycles very often. Since we primarily carry instead of towing we really do not miss the diesels. The gas trucks have been extremely reliable and less headaches with DEF and other diesel fuel additives.
Your biggest impact to fuel economy is going to be the quality of fuel and elevation you are running. Unlike a gasoline powered engine, diesels have a tendency to like warmer weather. Higher elevation means less air density. Higher temperature means less air density, but typically the turbo makes more than enough to compensate. Warmer air. Moving into the engine means a hotter combustion cycle, which means more complete fuel burn. In my opinion, still the best truck available in the halfton range. And I will be shopping for one this weekend. I would hunt around and try the various fueling stations. To see who has the highest quality diesel, it could be that where you normally go changed their vendor or their vendor changed something in the supply chain. I know for my Dodge, I found that what we call Fred. Meyers in my area was the highest quality diesel. I could get. Compared to most other vendors in my area, it was a difference of six miles per gallon.
Every time I visit corpus from San Antonio it feels like going down hill because you are dropping elevation. My gas mileage is so much worse coming home from corpus.
Hey JD. Glad to hear that you are still getting good fuel economy with the new 3.0 Duramax. How is the fuel economy in your 2017 F450? We just traded our 2011 GMC Sierra 3500HD Denali crew cab dually in (only has 68k miles on it but needed a new turbo) for a 2017 Chevrolet Silverado 3500HD LTZ crew cab dually (32k miles on it). The 2011 was getting about 16 MGP and the 2017 is getting about 19 MPG.
On that trip I always expect better fuel economy going to Corpus Christi/Padre Island at sea level than on the way home to Boerne at 1400ish feet above sea level, be it in a diesel or gas truck. I try to run non-ethanol in my gasser for the better fuel economy.
I have a deleted 2500 Cummins, leveled on 35x13.50’s and just did a 1000 mile round trip to Destin and averaged nearly 18mpg with cc set to 80 most of trip. I was pleased with that. I’d be curious to see how much a lift and 35’s would affect the mpg on the LZ0.
Fuel economy is just an average from the ECM basically a guess you should do your total miles divided by your gal when you fill up to get the accurate number.
Well I've been driving semi trucks for 24 years and I do my total miles / my gal all the time and it never matches the dash in my semi or my pickup truck
It's all good having a vehicle get good fuel MPG. But this is a truck. What kind of MPG will it get when you put an average size travel trailer behind it and tow it 300 miles?
I have 2023 LZ0 that I got over a year ago. Drive from central Virginia to WVA mountains, 28mpg going 33mpg coming home. Temperature has not effected it but wind and rain does. 50k miles and love this engine! Best 35mpg on 50 and 28.6mpg on 450.
I have something you should research and that is the amount of bio in your fuel. Bio diesel has fewer BTUs than pure diesel. In my state Bio can be anywhere from 5 to 20%. If Texas has similar requirements that might explain your part of your inconsistencies.
My 3.0 Ecodiesel gets about 30 to 32 mpg on a fairly level highway at 60mph. It drops off if I am going 70 to 75, and if I am fighting a headwind. It also drops off if my system goes into the "regen" mode to clean the exhaust system.
Heat and wind most likely…. Have you verified truck computer calculations by doing manual calculation after filling up? How is the oil consumption between oil changes and DEF consumption while towing?
Hey JD, off the top of my head I could think of a couple of things that could change the fuel economy. First is a dirty air filter and second would be the temperature. Hot air and humid could really affect the fuel economy.
Wrong…I only plan on keeping it 100k miles if I bought a gas engine it wouldn’t get 28 mpg! It’s not a 5.9 Cummins that will log over 500,000 miles nor a duramax that’s designed to last 400,000 miles. But it wasn’t a 10k up charge like duramax engine cost in 2002 it’s 900$ more than a gasser and will pay me that back in fuel savings. I totally disagree.
Roughly $3000 to have someone else change the oil pump belt at 150K. However if you tow every day it will save you a lot more fuel vs a 5.3 than if you're just kicking around the suburbs.
![Cody Johnson - I'm Gonna Love You (with Carrie Underwood) [Official Music Video]](http://i.ytimg.com/vi/yy9PuYMU29g/mqdefault.jpg)
Hot air is less dense, requires more boost to produce power, which requires more fuel. Same thing at elevation. Not surprising fuel economy dropped in hot temps.
I make that trip between SACC pretty regularly in a 6" lifted F-150 Platinum with the 5.0. I always get considerably better mileage from SA->CC, than I get from CC->SA. I always thought the elevation was the cause of it for me, since I usually make that drive in the heat of the day both ways. With the V8, lift, and bigger AT tires, I get around 16 mpg from SA->CC and 14.5-15mpg from CC->SA.
I drove from Pa to Cocoa Beach on July 7th. When I left I was getting 14.8 with 20x10 -24 offset and by the time I got to cocoa I was getting 16.3. On the way home I got 16.8. I have the 5.0 also with a level kit!! If I used my stock wheels and tires I could have got around 22mpg I’m guessing!!😎💪🇺🇸
Try switching to Amsoil lubricants and fuel additives and re-run the trip. I would be interested to see the results.
I hit 40k on my 21 rst 4x4 3.0!! I'm still averaging 31 Mpg & 700 miles per tank. 95% highway miles @ 68 mph.......
Try using diesel clean or the ACdelco fuel additive and watch those mpg come back doing it in my 2023 RST and 32 in my average here in Arizona
Corpus to SA and back is not the best test, it's uphill most of the way to SA and the prevailing wind is a headwind on the way back to CC. SA to Dallas would be a better one.
Corpus Christi elevation is pretty much 0 at sea level. San Antonio elevation is 660 ft. There's your answer.... climbing to San Antonio going down hill to Corpus Christi.
660’ in 145 miles driving distance is pretty insignificant elevation gain and should not increase the workload on the engine at all - wind maybe more of a factor
@@kaivonmortazavi8656 There's no free lunch. You are climbing to 660 ft using more energy. But yes wind is also a factor.
What cabin temperature have you set with the high outside temperatures being as high as they’ve been. The Air conditioner unit will mess up your mileage. I’ve noticed my MPG have dropped off a bit this summer.
I haven't had a milage change in my baby deisel yet. But, I did just got her back from the dealer after three weeks of waiting. She had an ECU / Emissions issue. Let us know if you experience the same. I'm just over 9500 on my 2022.
That’s a lot of miles for a break In period Oil change I always change the oil before 3000 miles the first time, my 2002 durmax still runs strong with many miles. Regardless of what the dealer says. It’s only 7 quarts and easy to do. My $.02
Is it maybe stuck in regeneration? Heat never makes a difference in my dually. Wind, regen and Gtade are the worst
It's a turbo thing. The 2.7L turbo engine is the same way. Mileage is much better when it's cooler out.
I am getting a titan fuel tank 43 gallons
When you get 24 mpg with a 5.7 Hemi 321 gears and factor in diesel prices and def fluid oil changes etc, I'd say v8 can't be beat 😊
At 79-80 mph this is what I would expect on a hot day with a 6000 lb vehicle, not knowing the wind direction I’d say it’s within regular operating economy, 80 mph is very fast in my world
Wind direction and wind speed is the biggest factor affecting mpg. What were they in this trip vs last test?
The quality of diesel can also make a difference in your mileage also I have learned modern diesels are very sensitive to the quality and condition of the fuel filters
I have a 2022 Chevy RST with the baby Duramax and love it. Super smooth and quiet. Have about 28K miles on it so far with several long trips (Montana 2x, Florida 1x, Michigan to NY 4x). My best range and mileage for an *entire tank of gas* was 660 miles and 28mpg. It will do 50 mile stretches averaging 32+ mpg easy. The two biggest MPG killers are wind resistance and elevation change. JDs experience here is pretty consistent with mine - set the cruise on 80mph and it will get you 24mpg all day. But slow down to get peak MPG. All things being equal, on the open highway, for every 2 MPH slower I drive, my MPG will go up by 1. Headwinds and cross-breezes can be challenging, though - still driving a giant metal box! Other factors that hurt MPG: road surface, temperature, quality of diesel (winter mix vs. summer mix) and tires. It regens every ~500 miles but the MPG drops for about 15 mins then roars back. Interestingly, I've done most of my best mileage when the truck is loaded right up. Towing is obviously a different story but still great by comparison. Pulling a 4000lb box trailer around town and a little highway mixed in, I average 17-18 mpg. The truck is just so capable.
How do you know when your truck is going into regen? I think mine did it on my NC trip because I think I smell some burning like the manual says.
@@nathanielwashington9775 I never know for sure, but there might be a slight increase in engine temps or I might smell it a bit, but the most reliable indicator is the drop in avg MPGs. Example: my 25 mile average might drop from 28 to 22 for about 15 mins, then it will creep back up for the next 20 mins. On long road trips, it tends to happen around every 500 miles and soon after a fill-up. I wish there was an indicator on the display that lit up when it was in regen.
Love your videos, but you can’t drive a shoe box 80mph and complain about mpg. I’m willing to bet my 6.2 that if you drove 2 mph under the speed limit, say 68, you would have gained 3-5mpg.
If you hit a regen cycle on a trip like that it will drastically change the MPG. My Equinox TD could vary by 5 mpg on some trips due to a regen cycle.
Wait. They offer a diesel in an equinox?
@@ML-lg4ky yes i think 2018 or 2019 only. I only found this out after I bought a 2020 a few months ago. I shouldve looked for the diesel(YES IN THE US)
Regens, hot ambient temps, wind, speed, hills, diesel fuel all can have huge impacts on mpg
80 miles an hour, in truck, GO FIGURE!!!! That's really good for 80.
I seen 79mph one way and 76ers the other. The difference between 76mph and 79mph is 4+mpg for my Jeep. It tracks IMHO.
Speed kills, slow down and mpg will improve like when you left San Antonio.
On my 2024 ZR2 with 3.0 wind speed and direction is biggest factor. On calm days I don’t see much difference between 85 and over 100F. It is 35% better than my 6.2L 2023 ZR2
Air density is affected by temperature, but also by humidity...gas turbines use inlet fogging to increase humidity and cool air inlet to the compressor. Higher humidity equals Higher mass air flow, cooler temperatures equals more efficient compression.
Once again, keep your wife happy. Keep the truck and give it to her to drive full time. A happy wife makes for a happy life.
I'd like to see a Powerboost do the same trip at the same time to compare MPG's. Everyone says the GM seats aren't particularly comfortable, and that is a deal breaker IMO, even with great MPG's.
Check out the ram ecodiesle I have the 10th anniversary edition with the air ride suspension and fully decked out interior. Do a side by side and drive. Think you really can’t beat either of those trucks. Mileage on fuel is amazing.
I agree the seats are not as comfortable on long trips. I filled up in NC with a range of 696 mi! I traveled 576 miles to TN, 31.7 mpg and average speed 62 mph. I set my cruise to 73 mph.
I have a little over 10K miles and the fuel economy is getting better and better!
JD, did the truck perform a regen cycle during your trip ? A regen cycle will consume ALOT of fuel and drastically lower fuel economy. The ultra low sulfur diesel fuel we have access to nowadays is simply trash. Im in the railroad business and we’ve totally abandoned diesel 3/4 and 1 ton trucks. Very problematic in winter time during idling situations. DPF would always get clogged therefore causing the trucks to go into regen cycles very often. Since we primarily carry instead of towing we really do not miss the diesels. The gas trucks have been extremely reliable and less headaches with DEF and other diesel fuel additives.
When I got my truck in 2023 diesel 3.0 I was averaging 13 at begginjng now I’m at 17.9. It’s bad my 2022 was really good .
Your biggest impact to fuel economy is going to be the quality of fuel and elevation you are running. Unlike a gasoline powered engine, diesels have a tendency to like warmer weather. Higher elevation means less air density. Higher temperature means less air density, but typically the turbo makes more than enough to compensate. Warmer air. Moving into the engine means a hotter combustion cycle, which means more complete fuel burn. In my opinion, still the best truck available in the halfton range.
And I will be shopping for one this weekend. I would hunt around and try the various fueling stations. To see who has the highest quality diesel, it could be that where you normally go changed their vendor or their vendor changed something in the supply chain. I know for my Dodge, I found that what we call Fred. Meyers in my area was the highest quality diesel. I could get. Compared to most other vendors in my area, it was a difference of six miles per gallon.
Interesting
So, driving 79 mph uphill gets worse milage than 76 mph downhill? No way! Most EPA milage figures are at 55mph. Bless your heart.
YEPPPPPP YOU= R FROM THE SOUTH😂
Every time I visit corpus from San Antonio it feels like going down hill because you are dropping elevation. My gas mileage is so much worse coming home from corpus.
Change your oil don't use GM recommendations, your fuel economy should improve.
As I remember, you weren't driving 79mph in the first video.
Fuel economy goes down as speed goes up on the way up doing 79 mph way back 75 to 76 makes be difference
Hey JD. Glad to hear that you are still getting good fuel economy with the new 3.0 Duramax. How is the fuel economy in your 2017 F450? We just traded our 2011 GMC Sierra 3500HD Denali crew cab dually in (only has 68k miles on it but needed a new turbo) for a 2017 Chevrolet Silverado 3500HD LTZ crew cab dually (32k miles on it). The 2011 was getting about 16 MGP and the 2017 is getting about 19 MPG.
Speed is probably a more important factor than temperature?
On that trip I always expect better fuel economy going to Corpus Christi/Padre Island at sea level than on the way home to Boerne at 1400ish feet above sea level, be it in a diesel or gas truck. I try to run non-ethanol in my gasser for the better fuel economy.
I have a deleted 2500 Cummins, leveled on 35x13.50’s and just did a 1000 mile round trip to Destin and averaged nearly 18mpg with cc set to 80 most of trip. I was pleased with that.
I’d be curious to see how much a lift and 35’s would affect the mpg on the LZ0.
80 miles per hour isn’t going to give you better fuel range.
I have a 22 Silverado 2.7l gas just did a trip and got just over 24 both ways i was so surprised
Air conditioning.
That is significant drop
1or 2 acceptable
Fuel economy is just an average from the ECM basically a guess you should do your total miles divided by your gal when you fill up to get the accurate number.
With today's vehicles, they know your precise speed and fuel flow rate. No need for the computer to guess anything
Well I've been driving semi trucks for 24 years and I do my total miles / my gal all the time and it never matches the dash in my semi or my pickup truck
It's all good having a vehicle get good fuel MPG. But this is a truck. What kind of MPG will it get when you put an average size travel trailer behind it and tow it 300 miles?
Possibly some bad fuel, or regen?
Ac running?
I have 2023 LZ0 that I got over a year ago. Drive from central Virginia to WVA mountains, 28mpg going 33mpg coming home. Temperature has not effected it but wind and rain does. 50k miles and love this engine! Best 35mpg on 50 and 28.6mpg on 450.
I have something you should research and that is the amount of bio in your fuel.
Bio diesel has fewer BTUs than pure diesel. In my state Bio can be anywhere from 5 to 20%.
If Texas has similar requirements that might explain your part of your inconsistencies.
2023 lzo heavy duty suspension 4by 4 75 mph 24mpg 55mph 36mpg Illinois in the summer love this truck
I have a 2022 1500 AT4, any one notice the paint jobs on these trucks are horrible, they scratch so easily
My 3.0 Ecodiesel gets about 30 to 32 mpg on a fairly level highway at 60mph. It drops off if I am going 70 to 75, and if I am fighting a headwind. It also drops off if my system goes into the "regen" mode to clean the exhaust system.
Heat and wind most likely…. Have you verified truck computer calculations by doing manual calculation after filling up? How is the oil consumption between oil changes and DEF consumption while towing?
Thanks for this review!👍🏻
I remember being a kid and we had a diesel in Houston. Everytime we took that puppy on a summer road trip vs winter my Dad would comment about it 😄
Hey JD, off the top of my head I could think of a couple of things that could change the fuel economy. First is a dirty air filter and second would be the temperature. Hot air and humid could really affect the fuel economy.
There are a lot of factors that effect fuel mileage. I have the same motor in my truck and take repeat trips with varying mileage
Different fuel blend possibly, heat, water grains/humidity, last regen, open road and wind direction. A lot of factors that have to line up.
The electric fan is probably running at full max speed it draws a lot of juice out of the electric system more load on the engine
The intake air density is different and the hot outside air with the incoming hot air you can’t cool the charge is efficiently. Cooler air is better.
The higher humidity, there in South Texas should have...and probably did give you the mpg that you got before it got hot.
If you've ever wondered about Cold Air Intake, regarding efficiency...now you know
Are you using a lot of DEF and is your truck using oil? I am interested in buying the diesel.
I would have expected much better fuel economy on that trip. Nice truck.
Hot humid air is the reason for the lower fuel economy.
If you refer it makes a drastic change to your trip
28 is pretty good for this truck
Head winds make a major difference.
Speed weighs heavily on mpg.
it could have been in regen mode
Changed that air filter yet?
How large is the gas tank? I missed it.
24 gallons, seems small but that’s usually over 500 miles range empty.
AC?
There is no benefit to this engine. It will inevitably be a trash motor that is too expensive to work on or maintain.
Wrong…I only plan on keeping it 100k miles if I bought a gas engine it wouldn’t get 28 mpg!
It’s not a 5.9 Cummins that will log over 500,000 miles nor a duramax that’s designed to last 400,000 miles. But it wasn’t a 10k up charge like duramax engine cost in 2002 it’s 900$ more than a gasser and will pay me that back in fuel savings. I totally disagree.
Roughly $3000 to have someone else change the oil pump belt at 150K. However if you tow every day it will save you a lot more fuel vs a 5.3 than if you're just kicking around the suburbs.
@@jakesvideos8204 it's a good play if you're only keeping a truck 100K either way.
Does it use a lot of oil? My 2023 Denali uses oil. Matter of fact it’s a the dealership now for oil consumption test