GREENVILLE, S.C. — Michelin North America Inc. has released 20 more sizes of the BFGoodrich All-Terrain T/A KO3 The tire ...

These tires will also work on 991.1 911 wheels, which would be the 2012-2016 models. The tire sizes will be P245/35R20 for the fronts and P305/30R20 for the rears.

For example, if the overall diameter of a tire package offered by the auto manufacturer is to be 29 inches, an 18-inch wheel would have a 225 65 R 18 tire, whereas a 20-inch wheel would need a 255 ...

And the 15 is the size of the wheel it's designed for. So, in this case you've got a 31-inch tall tire for a 15-inch wheel. You know the wheel radius is 7.5-inches, and the tire radius is 15.5 inches.

But as the arms race to present bigger and badder-looking wheels took hold at OEMs, the wheel sizes have shot up, with factory-available sizes above 20 inches now fairly common.

If a driver gets a tire with the same diameter but the width increases, it's a Plus Zero. Whereas, if the car comes with 20-inch tires and you want 22-inch tires from one of the major tire brands ...

If a driver gets a tire with the same diameter but the width increases, it's a Plus Zero. Whereas, if the car comes with 20-inch tires and you want 22-inch tires from one of the major tire brands ...