[DeTomaso] it wasn't that much fun

[Daniel C Jones]

Your really can't make a blanket statement that 315 is better than 335 on
the rear.  The effective roll stiffness (a function of both the spring
rates and sway bar stiffness at both ends), the weight distribution,
alignment settings, chassis flex and tire compound all factor into how the
tire contact patches are utilized.  Also, if you look at some of the 315
and 335 tires, you'll see the 335's sometimes have a smaller effective
contact patch. That was the case with the 335/35/17 Dunlop SP8000's.  They
have wide channels for better wet weather performance that reduce the
contact area.  Furthermore, you can not read across how a car with a
certain size race tire (and corresponding alignment) behaves when the same
car is fitted with street tires. This can even be the case within the
street performance tire category.  I once had a set of Z-rated Firestones
on my 1987 Mustang GT (lowered, chassis stiffened, Ford Motorsport springs,
Bilstein struts/shocks, caster/camber plates, adjustable upper rear control
arms, HPM Megabite lowers, poly bushing, etc.) and the car had major
oversteer.  I switched only the tire make (same sizes all around) and the
car was transformed without even a hint of oversteer.

Dan Jones