I got a new (2000 miles) 2007 Silverado with the 6 cyl engine. What does the button do on the end of the shifter lever? I thought it was to take it out of overdrive when pulling a trailer (little trailer light comes on in the dash display). When I push mine, there is no change in the RPM's. Today, the RPM's were showing about 1800 at 70 MPH in cruise control. Pushing in the button did nothing to the RPM's nor did I feel any shifting take place.

Also, my truck is getting lousy gas mileage. 13 town, 15 highway.

 

The tow mode on the end of shifter, will kick out i think around 50 MPH, so hitting the button when going down the highway, won't do anything.

 

it's a tow/haul button. at lower speeds it will shift firmer and wait longer to shift between gears. usually it will still go into overdrive around 70 though so that may be why it didn't do anything... i dont know what to tell you about the mileage

 

is the poor milage just with the tow/haul pressed, or all the time? If all the time, then could be alot of things like fuel filter, air filter, maf, cats clogged, etc.

 

couldnt be any of that with only 2000 miles, could it?

 

Oh, I missed that part, sorry. You are right it shouldn't e any of that. I would check the MAF though and make sure its hooked up and clean, and check for any blockage in the airbox.

 

Don't forget about the tires make sure your tire pressure is where its supposed to be at.