Well I have been running the juice/attitude since the second week I bought the truck and have noticed really bad gas mileage for a regular cab... I checked the tire size option on the attitude and it was set on the wrong circumference... it was set on 2524.2mm, but my tire size is 2430mm... my last tank of fuel I got 463 miles out of it @ 31 gallons... what does the smaller tire circumference make the "actual" mileage come out to be? because with the bigger circumference, I would have been running less miles than I really was.


Dan

Do you have stock tire size? If so your fuel mileage would be 14.94 mpg. The attitude doesn't change your OEM speedometer or odometer. So if you have the 245/75/16 your mileage is exactly waht it should be.

Thanks Max, that sucks though... my mileage seems to be really bad, but... I think it is because I live in a small town and a lot of my driving is 5 minutes and shutoff all the time, rarely do I take a trip over 20 miles... I'm new to diesels, but if I remember correctly, diesels don't use as much fuel at idle, but do use a lot of fuel on start up... could that be contributing to my bad gas mileage? I never really run it hard and don't tow a lot. What's the best edge/attitude setting for gas mileage?


DanEdited by: StraitDiesel

I USE MINE ON LEVEL 3 AND SEEM TO GET A LITTLE BETTER IF YOU JUST BABY AROUND EVERYWHERE BUT I DRIVE LIKE I WANT ENDS UP BEING 13.5.....LEVEL 1 AND 2 ARE WORSE

Thanks Max, that sucks though... my mileage seems to be really bad, but... I think it is because I live in a small town and a lot of my driving is 5 minutes and shutoff all the time, rarely do I take a trip over 20 miles... I'm new to diesels, but if I remember correctly, diesels don't use as much fuel at idle, but do use a lot of fuel on start up... could that be contributing to my bad gas mileage? I never really run it hard and don't tow a lot. What's the best edge/attitude setting for gas mileage?


Dan





The engine won't be fully efficient until it reaches operating temperature. And the engine is extremely efficient so it takes a few miles to reach operating temperature (more energy converted to locomotion and less converted to heat in the process).


I think I also read here that the transmission will shift and slip differently until the engine and tranny reach operating temperature.


Net is that you won't have good fuel mileage with short trips where the engine isn't already warmed up...


- jeff


Edited by: dmax lover

The other thing is that the Duramax is a low compression diesel and isn't as good on fuel at idle or cold as say the older 6.5TD. I have really noticed that. Once warmed up on a decent trip it seems to be much better on fuel and the power is amazing.