Tyres

THE WHEEL & TYRE BIBLE

Are you confused by your car tyres, or if you’re American, your tires? Don’t know your rolling radius from your radial? Then take a good long look through this page where we hope to be able to shift some of the mystery from it all for you. At the very least, you’ll be able to sound like you know what you’re talking about the next time you come and see us to get some new tyres.

HOW TO READ YOUR TYRE MARKINGS

This is probably the number one question I get asked – “how do I read my tyre markings?”. It’s confusing isn’t it? All numbers, letters, symbols, mysterious codes. Actually, most of that information in a tyre marking is surplus to what you need to know. So here’s the important stuff:

Key Tyre Marking Description

A) Manufacturers or brand name, and commercial name or identity.
B) Tyre size, construction and speed rating designations. Tubeless designates a tyre which requires no inner tube. See tyre sizes and speed ratings below. DIN-type tyre marking also has the load index encoded in it. These go from a load index of 50 (190kg) up to an index of 169 (5800kg).
C) Denotes type of car tyre construction.
D) M&S denotes a car tyre designed for mud and snow. Reinforced marking only where applicable.
E) Pressure marking requirement.
F) ECE (not EEC) type approval mark and number.
G) North American Dept of Transport compliance symbols and identification numbers
H) Country of manufacture.

As well as all that, you might also find the following embossed in the rubber tyre marking:

The temperature rating – an indicator of how well the tyre withstands heat buildup. “A” is the highest rating; “C” is the lowest.

The traction rating – an indicator of how well the tyre is capable of stopping on wet pavement. “AA” is the highest rating; “C” is the lowest.

The tread-wear rating – a comparative rating for the useful life of the tyre’s tread. A tyre with a tread-wear rating of 200, for example, could be expected to last twice as long as one with a rating of 100. Tread-wear grades typically range between 60 and 600 in 20-point increments. It is important to consider that this is a relative indicator, and the actual life of a tyre’s tread will be affected by quality of road surfaces, type of driving, correct tyre inflation, proper wheel alignment and other variable factors. In other words, don’t think that a tread-wear rating of 100 means a 30,000 mile tyre.

Encoded in the US DOT information (G in the tyre marking above) is a two-letter code that identifies in detail where the tyre was manufactured. In other words, what factory and in some cases, what city it was manufactured in.