Improve MPG

[gemarsh]

Currently over the 7000 mile range and it is averaging 12 MPG
I did ease up on the lead foot and it did help but not much. I was expecting much better MPG when I bought my GMC. but I realize that it is a gas hog.
Love Diesels but hate the DEF. I did read the DEF removal would greatly increase the MPG.

Deleting the DEF system alone will have no effect on fuel mileage.

 

AT4 Forum Fav 👍

Sellars Toolbox Shop Towels Dispenser Bucket - Grab one through Amazon!

[pinebaron]

Currently done only around 900 miles on my Duramax 6.6L V8. To town and back 21 miles each way, rural and highway, I'm getting 14.3mpg. I found tire pressures affected mpg a lot. Factory tire pressures worked best, 53-55 all around.

 

[pinebaron]

Last weekend we drove up to Whistler BC and beyond, then back home, over 300 mile round trip, up and down sea to sky highway, it was a great drive except the fancy seats could have been a little more comfortable (working on that and they may soften up a bit). Overall 14.94 mpg on the 2024 Duramax 6.6L V8 (now 1734 miles on the clock) , not great but not bad either, I did not purchase this vehicle for mileage, only for fun. I had reduced front and rear tire pressures to 45psi to improve comfort, wife was happy.

 

[BlackAT]

I have 8800 miles on my duramax and am averaging 13.3 with a daily mix of highway and city.

 

[pinebaron]

I have 8800 miles on my duramax and am averaging 13.3 with a daily mix of highway and city.

Sounds about right for that mix.

 

[pinebaron]

This was yesterday. With just over 3000miles on the truck it's getting even better mpg a huge diesel engine

 

[GreenGiant]

Wow! What a difference than the GMC Sierra AT4 with the 3.0 Diesel I recently purchased. I am on a trip right now and averaging right at 25mpg hwy. I have git as good as 31 on trips. Average around town is 21-23ish.

Hi GEK, good for you! But not relevant to this thread. The 3L diesel isn't available for HDs, which are also much heavier and perhaps more wind resistance.

 

[GreenGiant]

I have a '22 AT4 HD gasser. Mostly around town I get about 12mpg empty, 8-10mpg when I tow, possible to get 14+ on freeway empty.

 

[yzf1999]

Same with my 24 HD gasser…city driving my mileage is around 12 average and highway 14+ also…my city mileage is also affected because I pre start the truck 15 minutes to let it warm up when it’s under 30 out and 10 minutes when it’s under 50 outside.

 

[pinebaron]

It does appear that my 24 HD 6.6L Duratrax diesel is doing great for mileage, averaging over 15mpg in town and shorter trips too. To be fair, I drive the speed limit, avoid a lead foot and avoid my native British tendency to catch up to the vehicle in front no matter how fast they are going

 

[MATTE4]

Only 1400+ miles so far, but getting 15.4 combined with city driving. But highway unladen I averaged 21.8 on a 2 hour round trip on mostly open flat country roads maintaining 58-62 mph. A similar 2 hour trip with highway speeds 68-72 mph, mpg dropped down to about 17.5 mpg. That extra 10 mph sustained cost at least 3-4 mpg. Overall, pretty impressed with the efficiency running stock AT4 HD with psi 62 front / 70 rear.

 

[Paveslave]

Currently over the 7000 mile range and it is averaging 12 MPG
I did ease up on the lead foot and it did help but not much. I was expecting much better MPG when I bought my GMC. but I realize that it is a gas hog.
Love Diesels but hate the DEF. I did read the DEF removal would greatly increase the MPG.

A lot in of off-road testing in another country. I noticed the four MPG change on a 6.7 Cummins.