I just joined your group after purchasing my first new Silverado. After a lot of research and talking with a mechanic, I decided to go with a 2007 Classic, I would rather have a model that has been tweeked for 8 years instead of 8 months. I bought the extended cab with a 4.8 L auto and tow package. It has a 3.73 rear end and locking diff. So far I am quite pleased with it. I checked the mileage on the first tank and found out that I got 15.6 mpg around town. I am not sure if the tow package will effect fuel economy or not. My question is, Will the mileage increase much after the engine is broken in? If so, how many miles will I need to put on it before the mileage improves? Thanks Guys!

 

I have an 07 classic,ext cab...5.3 with a 373 axle..

it averages 19ish...it did rise a bit after about 2000 miles.
keep your foot out of it,and it should bump 20....does it have the steering wheel controls to figure mileage?

 

I have an 07 classic with the 4.8 and 5500 miles, my mileage averages at 17 mpg, but thats a lot of city and California stop and go freeway driving. Good freeway sailing is 20ish.

I just descreened my MAF and installed a Throttle Body Spacer today. Have noticed a moderate performance gain in the form of better throttle response. I'll let you know how much it affects mileage. Welcome and congrats on the new Chevy!
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Thanks for sharing your experience. I do not have a mileage computer on my DIC so I just figure the mileage at each fill up. I understand that the installed calculator is not real accurate. I was a little concerned that the 3.73 gear ratio would be bad news at the gas pump, but it sounds like it will only cost me 1-2 mpg. It's still amazing that the full size V8 Silverado gets such good gas mileage. My neighbor has a Toyoto PU with a "For Sale" sign in the window. He told me that it gets 11 mpg and he can"t afford to drive it. I guess Chevy owners don"t have too much to complain about

 

very true...

we traded for the 07 just a month or so ago...we had an 05,ext cab,4.8..342 axle....

that thing could SUSTAIN 23.5 on an interstate....maybe 19.8 in town

 

Now you say that, WHERE IS BOWTIE? Man I hope he sees that before his truck comes in so he can cancel it.

Anyways, you will find on the highway that if you really lift on the gas to just where you don't lose speed (farther than you think, just play with it) you can get great milage. With each power improvement that gets harder though as the throttle response gets better, so harder to feather petal.