yeah, i dont know man, i heard the smaller engines get worse gas mileage compaired the bigger engine equiped trucks due to the fact that the little engines cant hold up to the weight of the truck. i have an 08 with the 5.3, and im averaging 13.9 mpg, and i think thats ****ty, and i have the K&N intake, and im getting a corsa exhaust within 2 weeks and from what i have talked to from customers at work, when you put an exhaust on, the gas mileage is much better then it was. so hopefully that is the same for me. i wish i were hittin 20mpg in my truck. i dream of that day. hopefully after my MAF and TBS and programmer i will be there. n i will have all that stuff real soon.

 

Programmers and tunes help mpg a ton as long as you/the shop set it all up correctly.

 

keep yer foot out of it...

and what's the axle ratio?

 

Sometimes that won't help either. Our work truck (06 Chevy 4.3) gets lousy mpg with 3.08s and the old man (63 year old employee) drives it all the time. My buddy's RAM has an 8ft. bed, 4x4, ext cab with a 4.7 and gets 11 mpg. I think its just a weight to hp ratio. No idea what the gear ratio is tho.

 

I have a 2008 Silverado 1500 with 4.3 litre,six, automatic, 2WD. The EPA estimate for this vehicle is the same as the 5.3 litre, eight, 15 city and 20 highway. I drive on traffic free country roads. I drive very conservative almost like an old lady(joke). My average mileage is 18MPG, can't seem to improve that number no mater how I drive. I bought the vehicle expecting closer to 20MPG. I am disappointed. The rear end is 3.23. Synthetic oil makes no diference. I expect a slight increase of 1MPG with a K&N filter which I have not added at this time. I should have bought the 5.3 litre as the reports on MPG seem to be slightly higher.

 

after a reckless driving ticket.. MY average mpg went up from 12 to 15 LOL.. (weird huh).. 2007 EXT Cab 8-cyl 5.3L