it's getting close to tire time. i have the factory 20's with 275/55/20's now with 3.92 gears. 17" tires are cheaper to buy and i have a set of the factory 17" wheels. if i were to get 245/70/17's would the gas mileage change at all?

 

You would have to weigh each wheel. The ligher the better.

 

If the wheels are lighter and the tires are smaller then you should get better mileage...just don't know how much better....

 

Yes, you will get better mileage, i don't remember how much, not that much, like 1.5 mpg's or something. I think the look of the 20's is worth it.

 

The other factor is the tread on the tires. Heavy duty off road tires eat up the gas no matter what their size over street tires of the same size.