I just picked up a set of chains at a garage sale and on the box it says they fit a 265-75R15, is that the same as the 31x10.5r15 I am running on my F150? Thanks.

 

Maybe you can answer I question I posted in another thread; I've got a 1996 2WD with the stock 235/75R15's on it. Can I use 31x10.5R15's without having to worry about body rubbing or lifting the truck? Thanks, Shilly

 

>Maybe you can answer I question I posted in another thread;
>I've got a 1996 2WD with the stock 235/75R15's on it. Can I
>use 31x10.5R15's without having to worry about body rubbing
>or lifting the truck? Thanks, Shilly

Yes you can.

 

Yeah the only problem I have is when I crank the wheel all the way the tires rub. That could be form the backspacing of the rim, I am not sure. What size rims are you running?

 

Yeah they're the same size. 265 millimeters is section width, the widest part of the tire halfway up the sidewall. 75 means that the sidewall is 75% as tall as the section width. So the sidewall is 75% of 265, or 199 millimeters tall. Two sidewall heights plus the rim height will give you the height of the tire, or 2*199 millimeters + 15 inches. 398 millimeters divided by 25.4 millimeters per inch = 15.65 inches, + 15 inches = 30.65 inches. And 265 / 25.4 = 10.43 inches of section width. So it's a 30.65 x 10.43R15, although due to the undersizing involved in tire sizes it usually ends up identically to a 31x10.50. The wierd part is, since rim size comes into account in the height of a metric sized tire, flotation sizes like 31x10.5R15 and a 31x10.5R16 would be the same height, but a 265/75R16 is an inch taller than a 265/75R15.

 

Thanks alot. I finally understand what the metric measurements mean.