[Walt Fricke]

Seems to me the phone dials are rather a heavy rim. A search for wheel weight ought to come up with a couple of charts guys have compiled.

Guys were thinking 17s were the hot setup for a while. Perhaps because they could add monster brake calipers without clearance issues. Or because they looked cool, had good tire selection, etc.

But it turns out that for both autocross and track use you are probably ahead of the game to use 15s, because you can get tires with a smaller diameter for them. This helps with accelleration, and it also keeps the unsprung rotating (inertia) weight down.

I've raced on 7x15 cookies for 20 years as fronts. And performance doesn't seem to drop off much if I run them, with the same tire size, on the rear. Sticky DOT tires, or full slicks, work fine with both. 225 is as wide as I think you'd want to go, with the lowest aspect ratio you can get. If you put too wide a tire on a rim, sidewall stiffness suffers.