I upgraded to OEM 18" wheels and tires on my '07 4.6 liter truck a few years ago and I'm wondering if I went back to the stock 17" wheel and tire if I'd see an improvement in mpg and acceleration. Best I can tell, the 17" tires are 6 lbs lighter than the 18s. Not sure about the wheels. Thanks.

 

Wheel size won't make a noticable difference at all. Tire size/tire tread pattern is the only thing that'll change your mpg enough to notice.

 

X2, you'll need to decrease the tire diameter and width to increase the efficiency and acceleration. Unfortunately to make any decent gains mpg wise, I think the truck would have to start looking more like a prius with tiny little wheels.

 

I could see a very small improvement from the loss of weight the truck needs to turn. But nothing worth the change over to a smaller wheel.

 

You would have to drop like 100-150 minimum pounds to notice any difference from weight and even that weight would be a very small difference.