GTA_Driver

If you install a larger diameter tire, then yes, the contact patch should be higher.

If you only install a wider tire, then it doesn't automatically translate to a wider contact patch.

Because the mass of the vehicle remains constant, the wider tire will have a wider patch across but a shorter one length wise, no? At the end, it ought to improve lateral road holding ability, but will it necessarily help reduce wheel spin?

It seems that tire pressure wil have a bigger difference on the contact patch then going from, say, 225 to 245 wide tire.

I remember drag racing and reducing rear wheel pressure to about 22 psi to help with the take off.

An even bigger difference will be made by the rubber compound in the tire.

Boston Driver

I use 235 45 17 on my fat fives for winter (narrower tire better for grip).

SloopJohnB@mac.com

You're right for the most part...here's an interesting link:
http://www.performancesimulations.co...on-tires-1.htm

F=PA is too simplistic. Like the movie, it's complicated.