Best Tire Brands -
|You may have noticed the letters and numbers on
the side of your tires. But what exactly does it all mean?
The letters and numbers, correspond to the ratings of your tires. Here we teach you what it all means, in plain English.
Let's use an example of a tire like P180/55R15 85T to teach you what it all means. The final 85T is known as the service description of the tire. This is gonna tell you the tires load index and speed rating.Tire manufacturers have been required since 1991 to display this information on the tire.
The service description is important, because it identifies the amount of weight the tire can carry and the maximum recommended speed of the tire.
The first two digits of the service description corresponds to the tires load index. So in the example we take the 87T, 87 represents a load index of the tire. The higher the number of the low index, the higher the carrying capacity of the tire. Below is a chart showing load indexes and their corresponding carrying capacity.
|The next important number is the speed rating, the
letter after the load index number, gives us the tires speed rating.
Using our example of P180/55R15 85T, the letter T will give us the tire
speed rating. In this case it's 118 mph or 180 kmh, this means that the
tire should never be driven faster than 118 mph. Of course, most
highways won't permit this type of speed anyways.
Below is another chart showing you the letter and corresponding speed rating for each tire. Z rated tires were originally designed to be the highest speed rated tires. Z means in excess of 149mph. However the V, W and Y ratings were later introduced, which further clarify the capability of these extreme speed tires.