Mpg?

[07VMax]

ok so i have a 07 nnbs Vortec max 6.0, 3.73 Gears, 4x4 and active fuel management and i get around 14 according to the dic. i also have an 05 Yukon Denali 6.0, 3.73 Gears, AWD and i get around 18 on the dic. so my question is why does the vehicle without afm, heavier and is always in 4x4 get so much better fuel mileage??

[Zembonez]

Run a tank through it and calculate your mileage manually. You might be surprised by the results. The DIC on my truck isn't very accurate one tank t a time... It's not too far off over long periods.

[07VMax]

yea that is the only thing i could think of was the dic being off on one of the trucks

[Zembonez]

Mine is as much as 1.5 miles off on a single tank fuel run. Over several thousand miles it is very close.

[flyin6]

As part of a performance tune my AFM V4 mode was turned off. I didn't actually know it had been disabled, but what I did notice was that fuel mileage increased everywnere. Anywhere between 3/10's to over a mile per gallon improvement over the stock tune and AFM enabled. The gentleman tuning my truck reported he got better mileage with the V4 mode disabled!

[00Silverado4x4]

In my '06 the computer seems to always over estimate my gas mileage, especially on "in-town" mileage. It usually shows 14-15 on regular & it's guaranteed to be more like 13-14 or lower depending on how mad I get at all the "Sunday drivers" I have to deal with. I always reset Trip A, Mileage Economy & Estimated Fuel used on every fill up. Are you suppose to reset anything at fill ups or let it carry on. I accidently reset the Mileage Economy one day while driving & it told me I was getting 45 mpg for about 10-15 miles until it calmed down to about where it was...try that in your truck.