Just wondering, a friend of mines girlfriend has an 07 tahoe w/ the same wheels and tires as my truck (20 inch akuza blades 285/50/r20 tires). The tahoe doesn't have any mods and he says that it only get about 14-15 mpg around town and on long trips. He said because of the bigger wheels it won't switch from the 8 cyclinders to 4 cyclinders on long trips Is this a common problem because I didn't think it would matter since most of the newer tahoes have 20's on them from the factory?

 

it may have 3.23 gears...if so, that's quite a load for the engine on the highway which may keep it from switching.

 

O ok ill check into it

 

this might be true, my wifes 07 tahoe is the same but it has 3.42's.... I bought it with stock 17"tires, then I bought some factory 20's right after I bought it and I noticed the same it hardly or pretty much never goes to V4 mode? but I just put the stock 17's back on and now I see it go to v4 mode more often still gets the same mpg, 18mpg on the highway, the only thing the tahoe has is a tune, I know it needs a retune cause it was tuned with the very first program that hp tuners came out with, which did not come with too many options to mess around with, I should be getting a retune sometime...

 

Is there any adjustability with the DOD?