Tire Question

[B'ham Jeeper]

Ok I have a "newbie" question. I have 18" wheels but I see alot of people talking about 33" tires. What size tires do I have? And what size tires will fit my wheels?

Thanks...

 

[currupt4130]

Look on the sidewall. You have 18" rims, you have a tire size that fits onto an 18" rim. Probably metric if they're factory.

 

[redrooster]

Your wheel has an outside diameter of 18". When people say 33" tires they are talking about the diameter of the tire.
Example: say your Jeep has 235/70/18 tires. 235 is the width of the tire in millimeters. 70 is the aspect ratio meaning that the sidewall is 70% as tall as the tire is wide. 18 means that it is designed for an 18" wheel.
If you want to convert the tire height to inches, it goes like this: 235mm x .70=164.5mm sidewall height. Convert that to inches: 164.5/25.4=6.47 (we'll round to 6.5") This means your sidewall is 6.5" tall. To get the overall height of the tire you add top sidewall plus rim plus bottom sidewall, 6.5+18+6.5= 31"
An Auburn fan should know this since all the mobile homes down there have at least 31" mud grips.

 

[B'ham Jeeper]

Dang I didn't know I was going to have to do math! Ok so my tire is a 255/70/18 and that calculated to 32". Does that sound right? (you know being and Auburn fan and all!) :lol:

 

[currupt4130]

http://www.4lo.com/calc/gearmetric.htm

 

[redrooster]

Sounds right. Now go out there and measure the true height with a tape measure. I bet it's under 30" mounted with weight on it.

 

[jfrabat]

Keep in mind that "advertized" size and "real" size varies... Meanining that you can buy a 32" tire that really measures 31", so dont count on the sidewall to be exact...