Tire Tech Page

Here is a breif break-down to introduce you to the world of tires... Please feel free to browse through the links at the bottom of the page as they may be filled with information you will find useful!

Look at the sidewall of a tire and you will find a numerical code, for example:

195/65/14

The first number (195) is the overall width of the tire, not the tread width.

The second number (65) is the aspect ratio. The sidewall is 65% as tall as the tire is wide.

The third number (14) is wheel size.

As a tire gets a lower aspect ratio, the tread gets wider, so a 195/60 will have a wider tread than a 195/70.

Figure out tire diameter as follows:
Width x (Aspect Ratio x 2) / 2540 + Wheel Size
195 x (195/65 x 2) / 2540 + 14

First: 195 / 65 = 3, then multiply by 2 = 6
Next: 195 x 6 = 1170, then divide by 2540 = .4606
Finally: .4606 + 14 inches = 14.4606 inch tire diameter.

A 205/60/14 is only about 1% shorter than a 195/65/14 but will have a wider tread width.

Here are some helpful links to learn more about tire tech that may help you in your racing. Traction ratings, speed ratings, tread wear and more are explained on some of these links as well as some helpful conversion charts.

http://www.miata.net/garage/tirecalc.html - comparison chart for rpms

http://www.dakota-truck.net/TIRECALC/tirecalc.html - tire size calculator

http://www.dsm.org/tools/tiresize.htm - tire size calculator

http://www.tirerack.com/tires/tiretech/general/utqg.jsp - tire tech

http://www.us23.com/tires/html/tire_info.html - tire terms

http://www.car-videos.com/tools/speedrpm.asp - speed/rpm calculator

http://www.onlineconversion.com/ - metric to standard conversion chart