'07 issues...

[White Out]

My dad just replaced his '04 awd Denali with an '07 Tahoe LTZ 4wd. With the truck in 2wd at 75-80mph it is only getting 13mpg. My brother's '07 Avalanche also gets about 13mpg on the highway. At 70mph the truck averages around 17mpg.
My dad's denali used to get 15mpg at the same speeds and his '00 Yukon XL would get around 17mpg at those speeds. Is there somthing that is wrong with the new trucks that isn't allowing them to come near their stickered ratings?

I also noticed that his truck runs over 210 degrees. On his past two trucks they have run well under 210. This seems pretty high for a truck with less than 1,000 miles on the odo.

Nick

 

[Getwired]

Ah, yes, welcome to the club! My mileage is not great as well, but I've got a 6.2L in the Denali. The mileage does improve over time, and you can give it some help with a cold air intake kit and/or a programmer, and synthetic oil on the first change. I was getting 9.9 city, 11 hwy. Now I get 12.5 city, 14+ on highway. Part of it is also keeping your foot out of it...

Let us know how it improves with some mileage!

 

[White Out]

hopefully it improves with time as it will never be modified or get synthetic oil.

Nick

 

[LAP TOP GAMER]

I am getting similar mileage as gearing makes a difference too, but it is a large vehicle so can't expect great millage.

 

[White Out]

But the truck is nowhere near it's posted mpg AND it is worse mpg than an awd truck with a bigger engine and it dosn't kick down to 4cyl mode.

This truck is barely getting better mpg than our '98 hummer open top.

Nick

 

[Rafael]

4wd ltz weighs more than a denali. What are the gear ratios? What tires in what sizes also matter. These things will effect mileage greatly.
My 07 4wd tahoe gets about 15mpg at 75mph, 17 mpg at 65mph and 19mpg at 60mph

 

[White Out]

no clue on the gearing. I know that he had the stock 17" wheels on the denali, but the outer diameter of the tire should be close, if not the same as the factory 20" wheels from gm. It would be more costly if the sizes were different because they would need to have different calibrations for different wheel/tire combos.

Nick

 

[slvrbrchyukon]

i have an 07 yukon 5.3 V8 and i have about 35k on it. Roughly, I am averaging about 15mpg with city and highway drving. Now depending on how I drive, I can surely get less and especially when I am pulling my trailer. Good luck with the new truck :thumbsup: