2022 Chevrolet HD Duramax

[Jonesy]

Geez, I have a 2020 GMC HD2500 with 6.6 gas and I love it. It looks like Im getting sbout the same MPG (14 and 17-18 HWY) as the 2022 Duramax. It says my best mileage was 19.6 for 50 miles.

The 6.6 gas engine is totally an upgrade from the previous 6.0.

[x33rs]

Originally Posted by Jonesy

Geez, I have a 2020 GMC HD2500 with 6.6 gas and I love it. It looks like Im getting sbout the same MPG (14 and 17-18 HWY) as the 2022 Duramax. It says my best mileage was 19.6 for 50 miles.

The 6.6 gas engine is totally an upgrade from the previous 6.0.

I've heard good things about the new 6.6. My dad has been contemplating trading his 14 3/4 ton in (6.0) for a 21-22 with the gas 6.6. Still the same 6L80 from what I've read but I think the larger engine has an easier time pulling that truck around and also doesn't use as much rearend gear to do it. I think they come with 3.73's and dad's came with a 4.10

[67since67]

2017 HD 2500 CC L5P D-Max, these are typical numbers empty and dragging the box at my usual 75-80. Under ideal conditions I did once see 15.5 with the trailer at 65mph (construction zone), and 28.6 empty with cruise set at 70 mph for 80 miles.
My D-Max is very sensitive to outside air temps and headwinds kill towing milage, and of course leaning on the pedal.

When this truck was new I had the dealer monitoring DEF usage as it seemed to guzzle the stuff while towing, which is 95% of it's usage. Over time that changed and now with 44K on the clock it's not an issue.

Other than recalls for seat belt and block heater it has been trouble free.

Bill W

[x33rs]

Do you guys figure mileage the old fashion way rather than rely on that computer screen?

I ask because I've found mine to not be all that accurate. It's actually a little happy.

My screen driving around town always says it's getting about 18 most of the time, probably an average figure, but even when it's just around town for weeks it doesn't change, not to mention that figure isn't even close to actual. Plus the gallons it says it uses is also on the light side.
It generally says I've used 2-3 gallons less than what I actually pump in the tank to fill it.

Basically I don't trust that thing and do the old "gallons pumped vs miles driven" method.