I own a 2007 Silverado four door and the Gas Mileage is so incredible I had to tell someone. I drive 170 miles interstate twice a week and decided to experiment with different speeds to see the differences in Gas Mileage. If I keep the truck at 55mph it averages 28.7 mpg. I found this so hard to believe I checked it with a calculator and it is accurate. At 70 mph it averages 21.3 mpg. Now granted this is all Interstate in Florida so there are no hills. And this is without using the A/C and no loads in it. But I never would have believed anything that size could do that well. Around town it is only 14 mpg since the 4-cylinder option rarely kicks in. But for highway driving that is just amazing for something as heavy as this truck. Just wanted to tell someone.

 

Thats pretty cool man. Glad to hear it with gas prices the way they are.

In PA its hilly but I still get 20 at 70, 19 over 70 and 22 at 55 as long as I don't pass often and traffic is low. I decided to start using the cruise control when driving 55. First of all I can't stay below 70 without it, and second it supposed to help fuel economy. Well I got about a 1 mpg increase using it so I use it all the time now.

 

yes,it'll do it..

my 07 classic hit the 26 range on i-20 thru the barren south..

and yes,there is a HUGE difference in 55 or 70

 

im not surprised my new 89 averages about 22 at 80. but ill drop down to 55 and see how much she goes up.

 

gm says optimal fuel mpg is about 48-55 mph ,depending on the axle ratio.....your neither pushing or pulling the truck,its rolling

 

Whats optimal for 3:73's?

 

i'm not sure,..but it would be closer to 55 than 48,i guess

 

my dad's 07 is getting about 14 highway (75mph) with the 4.8, hes pretty pissed

 

Whats the ratio on it? See 4.3s aren't always the best on newer trucks as the V8s are getting more fuel friendly......well GM anyway.