FW: [NAC] wide wheels with rather narrow tires

[Stephen Bigelow]

> Picking the right tire/wheel combination can lay much more rubber on the
> road in a 215 width than some do in a 225 width.
>
> I wish it were so simple.

Me too.

3000lbs car, 60/40 front rear
1800 lbs on front
900lbs per tire
35 lbs/sq inch pressure gives 25.7 sq/inches contact area.

A 225/60/15 Dunlop D60 shows a 7.1" tread width as measured on a 6" rim,
giving 3.61" tread length.

215/60/15, same rim, 6.9" tread width, 3.72 tread length.

http://www.tirerack.com/tires/Spec.jsp?make=Dunlop&model=D60+A2%2CD60+A2+JLB

(Yes, I *know* the relationship between tire pressure and contact patch size
isn't linear. My point is it is FAR more linear than tire width swapping,
which has almost no effect at all on patch size. Just shape, assuming
compounds and sidewall stiffness remains constant.)