Are secrets to life held in sidewall graffiti on tires? Author Douglas Adams might be intrigued at the notion, but the truth is that tire codes tell consumers about the tire’s size, wear, construction and speed rating, among other things. Using the right size tires for your vehicle is an important part of getting the most from your vehicle and increasing mpg. Thanks to all of our friends at Edmunds, here’s the official cheat sheet for breaking down the mystery of the tire codes on your daily commuter or weekend joy-rider. You will know what the sidewall graffiti means and only need to go to a Car Deal Expert when you need an auto loan.
Source for this article: Deciphering sidewall graffiti – What those tire codes mean?
If your tires could talk – sidewall graffiti
Let’s use 205/55R 16 89V as our example. Let’s see how it breaks down:
- First there’s 205 – Which measures the millimeter distance between sidewall edges, this is the tire’s section width. The bigger the number, the fatter the tire.
- Second there’s 55 – The aspect ratio that compares section height to width. The section height in this case is 55 percent of the section width. Lower numbers (under 55, for instance) mean a shorter sidewall, which grants improved handling.
- Third there’s R – This is the tire’s construction, in this case radial. Radial has been the standard for the past 20 years, but certain trucks still use the old bias-play construction.
- Fourth there’s 16 – This is the rim diameter in inches. If you want to upgrade your wheels, you’ll need a set of tires to match the new wheel size.
- 89 – The load index, which represents the Maximum Load-Carrying Capacity Per Tire chart. 89 equates to 1,279 pounds per tire. Get the total weight capacity of a set of tires by multiplying the weight by four.
- Sixth V – This represents the speed rating, which tells you maximum speed a tire can go over an extended period of time. A car can safely go 149 mph for a period of time with “V”. Go over that for too long (say for several minutes) and your tires may explode. For other speed codes, see the link at the bottom of the article.
In sidewall graffiti, other things to consider
Other information according to Edwards that might be important in the case of a recall are DOT numbers (Department of Transportation). A being the best, a traction rating of A, B, or C might available as well. The numbers 120 or 180 along with the word “TREADWEAR” might be visible. The industry standard is 100, so a tire with a 180 is designed to maintain acceptable tread for traction 80 percent longer than the industry standard. The higher the number, the longer the tread life, although sometimes other scales are used.
Find more information on this topic
Douglas Adams
http://en.wikipedia.org/wiki/Douglas_Adams
Edmunds
http://www.edmunds.com/ownership/howto/articles/43859/article.html
radial
http://en.wikipedia.org/wiki/Radial_tire
Maximum Load-Carrying Capacity Per Tire
http://www.kaltire.com/retail/about_your_tires/loadchart.php
speed codes, see the link at the bottom of the article
http://www.tirerack.com/tires/tiretech/techpage.jsp?techid=35


