To all of the 2008 Sierra 1500 owners out there, would you mind telling me (and any others with inquiring minds) what kind of average MPG you're getting with the varied uses you are putting your truck through? I'm curious what the actual numbers are with the adjusted-for-2008 EPA ratings. TIA!

Well you know mine is an '07, it was rated at 16/22. After 13k miles, my overall average on the DIC stands at 16.1 mpg.

Thanks ocn... in my haste, I forgot to include 2007 plus 2008.

How about all of our "All Terrain" owners here? Care to share your average MPG to date?

I don't assume the All Terrains are any better because they ride up higher, worse areodynamics, lower economy. But they look bitchin.

Well, I have a 07 Silvarado vortec max and in the summer with summer tires I can average about 17mpg but now I am closer to 14. This is 60-40 highway-city!

My 06 GMC 4x4 5.3 3.42 rear end. Avg MPG from home to daycare to work to home 16.1

Hwy 19 to 20

My 08 GMC All Terrain 6.0 373. Same run avg 15.9

Hwy 18 to 19

My 2008 Sierra All Terrain Z71 4X4 5.3 Flex Fuel 3.73 Gears, Highway Driving I have about 3000 miles on it. Running on Regular 87 Octane I have been averaging 17.5 mpg, Running on E85 I have been averaging 14.5 mpg. I am not to impressed my 2007 Sierra Z71 Crew with same engine and gears got alot better.

Yep that sounds about right we have 2 trucks that where replaced here at work last year, and they are getting no where near the mileage their older ones where. I think they are avg 17 something and they drive alot of hwy miles. With them avg 17 and me avg 15.9 close to 16 I am happy with what i get out of 6.0l I still get around 400 to 450 to tank of gas.

My 2008 Sierra Reg cab 4.8 V8 averages around 15 to 16 MPG... in a drive mix where 30% is downtown city street crawling and 70% is 70 mph freeway, with stop-and-go interruptions.

2008 Sierra Denali 2WD, 6.2L, 6L80E, 3.42 gears.

On my typical greater Houston area commute I average 13.5 MPG so far. Only 3400 miles on my truck, so it may get a touch better when fully broken in.

Well, my Sierra ventured away from the Houston city life... and made two major road trips this summer.

One trip to Pensacola, Florida ...and the other to Oldfort, Tennessee (not far from Chattanooga).

Florida was about 1050 miles round trip, Tennessee was 1700 miles round trip.

We calculated 18 mpg on the highway - running in the 70 to 80 mph range.

I can't complain.