Cool Tire Size Calculator Program

Post by **david58** » Fri Sep 28, 2007 4:24 pm

Ozzie · Post by **Ozzie** » Sun Sep 30, 2007 5:56 am

Anybody got the correct dimentions for a stock 155 x 15 tire?

David, you come up with the coolest stuff.

Post by **david58** » Sun Sep 30, 2007 6:48 am

Section Width
Following the letter(s) that identify the type of vehicle and/or type of service for which the tire was designed, the three-digit numeric portion identifies the tire's "Section Width" (cross section) in millimeters.

P225/50R16 91S

The 225 indicates this tire is 225 millimeters across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specified width wheel. This measurement is also referred to as the tire's section width. Because many people think of measurements in inches, the 225mm can be converted to inches by dividing the section width in millimeters by 25.4 (the number of millimeters per inch).

225mm / 25.4 = 8.86"
http://www.tirerack.com/tires/tiretech/ ... ?techid=46
Now your tire size needs the aspect ratio to use the next calculator.
http://www.miata.net/garage/tirecalc.html
I'm thinking it should be 65?

Tire Size Comparison
Specification Sidewall Radius Diameter Circumference Revs/Mile
155/65-15 4.0in 11.5in 22.9in 72.0in 879

kdf · Post by **kdf** » Tue Oct 02, 2007 10:08 am

I think it's 80% profile with radials unless the profile has been stated, that makes the diameter for 155R15 25.7 in. But according to a quick google some manufacture stated 26.1 in for a 155R15, 91% profile???