Maybe the ProComps are a smaller diameter than his old 305-50-20s?

 

Well not sure exactly how it has improved the gas mileage but it has. I do know that the 20's were much heavier than the 17's. The 20's were approx. 1-2" wider than my new setup also. I will d/l a couple pictures today and post them!

 

The rolling resistance is less on the 17" wheels than on the 20". The weight difference also plays a part in lessening rolling resistance. You are looking at 3 extra inched of forges aluminum per wheel, or a full 12 inches of forged aluminum per set. The rubber on the 17 inch tires is lighter than the aluminum on the wheels, plus, he went from 305 series tires, these are WIDE tires, the more rubber making contact with the road, the more resistance you get. Notice drag cars use skinny little front runners, usually 3 inch wide or so, to reduce resistance on the front end. So, to keep it simple, the less resistance, the better the gas mileage!

 

NEW PIC:


[IMG]local://upfiles/58211/87C3534C69314FBBB1D2C1B85CE8FF9C.jpg[/IMG]

 

true...among other things.

 

What kind of tires were you looking at that were $400 each? Mine were $200 each which is typical of the tires I usually put on my vehicles.

 

what tires do you have john m? and what size. id love to pay $200 a tire!

 

what size are those pro comp tires?

 

check these on tire rack, almost all are under 200.00$ some are just a tad over 100.00$

http://www.tirerack.com/tires/Compar...amp;loadRank=2

 

I have the perelli's on mine and they were about 150 each and they are great for my driving conditions.