Hayk

iTrader: (1)

Please educate me.

I've noticed that if you physically measure the diameter of your wheels, they're always an inch larger than what the manufacturer or the tire say they are. For example, my 205/65/15 tires are mounted on "fifteen inch" wheels, but if you measure them - they're 16". Why is that?

LeX2K

Interesting question. I'll take a wild guess and say it's because the smallest part of the inside of the wheel is where the measurement is taken from.

Hayk

iTrader: (1)

That makes sense, thanks for the response.

Power6

I hadn't ever thought to measure my wheels! I think the diameter measurement is where the tire lip seats, the edge of the rim on the face extends beyond that. I know I've calculated diameter of wheel and tire package and come pretty close just with wheel size, aspect ratio and tread width.

Oh Googled this looks like that is what it is