Something tells me I'm asking a very stupid question but here:
http://www.tirerack.com/tires/sizes/...sp?diameter=15
Also check this out to find out what i'm talking about
:
http://ecomodder.com/forum/showthrea...ling-2813.html
you can buy tires that are taller or shorter (distance between wheel and tire tread)....
which would be most fuel efficient, a very tall tire or a very short one? assuming same tire width, rolling resistence, etc.