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Tyre Markings

At the Total Kenya Motorshow I had a chat with some chaps at the Yana Stand who explained to me what the numbers on a tyre mean. Heres a summary

1.Tyre width
This three-digit number refers to the overall width of the tyre in millimeters.

2.Profile/Aspect ratio
The relationship between tyre height and tyre width. The higher the number, the taller the sidewall. The lower the number the smaller the sidewall, hence the term low-profile tyre

The letter R indicates radial-ply as opposed to bias-ply tyre construction.

4.Wheel diameter
This number indicates the size of wheel the tyre is designed to fit onto.

5.Load index
A relative scale that indicates how much weight the tyre is certified to carry at maximum inflation. It can range from zero to 279. The higher the number, the greater the load-carrying capacity.

6.Primary speed rating
This specifies the maximum speed at which a tyre is certified to carry its maximum load. Primary speed ratings range from A (lowest) to Z (highest). (Some tyres also carry more specific secondary ratings.)


5 Responses to “Tyre Markings”

  1. Good article on tires. Here in the states the DOT (Department of Transportation) requires one extra marking. The mark is for the date the tire was made. It is the last mark and will read: 0935 This means the tire was made in the 35th week of 2009.
    Thanks for your good article.
    Denis Foley

  2. Very nice car site with great articles. Thanks for sharing.


    Please visit us anytime.

  3. @DOT issue: I am sure there are even some tires 4 sale in EAK with three figures (= 1990s). But then, those who'd care about this probably also have the funds or interest in fresh tyres and not old material which has already hardened out.

  4. Thank you Dennis carol and jke for your comments

    ahh, the DOT! Changed the looks of many cars in the 70s with that single headlamp regulation and those ridiculously long bumpers. I might blog about it some day

  5. blu ray ripperblu ray ripperblu ray to aviblu ray to wmvblu ray to mp4Furthermore, Blu ray Ripper has powerful editing functions like Trim and Crop Blu ray clips, add text/image Watermark as a logo, set video Effect like brightness, contrast, saturation, etc.

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