2007 Silverado, regular cab, 4.3L, V6, 1000 miles.

Getting 10 mpg around town and 14 on highway. Window sticker says 17 / 21 mpg.

Should I be complaining to someone?

 

How do you drive?? That has a big part in how your vehicle will perform and how much fuel milage that you will get out of it. I guess it is brand new saying that it only has 1000 miles? Is it lifted w/larger tires? There are so many variables that you should look at before thinking that it is the truck itself. after all of that, take it back to the dealership that you perchased it from and let them know the same thing. Also don't tell them if you have been riding the truck hard. But most likely they will give you this speach. It is under 5,000 miles, it is still breaking in. Just try and get it in writing, this should help you if you do have a Lemon. Good luck!

 

One 500 mile trip so far. Averaged 70 mph on cruise control in flat coastal plains country. I'm 65 and retired and don't get in a hurry! Around town it's probably not more than 45 mph with average stop & go traffic.

Transmission is a little jerky when shifting. (automatic) I can feel it slip and see a momentary increase in RPM's.

Yeah, truck is new. Got it in August. Tires are stock P245/70R17.

 

once you hit the "turn around millage" when the motor is fully broken is and its running at its best you will notice the increase on milage i know the duramax turnaround millage is almost 30,000 mi

 

I would take it back to the dealer and find out when you could expect to get the milage declaired on the sticker. Also have them drive it and get the tranny checked out too. That is all that I can think of besides waiting to see if it gets better.

 

it will rise at around 5k...but that does seem low...non service lite on?

 

I`d say it`s darned awful low too. My 05 K2500HD with the 6.0 got better mileage first day off the lot than what you`re getting.