Have you ever looked closely at the letters and numbers printed on the sidewall of your car tyres? You may have seen a combination of letters and numbers that may have seemed like an encoded message. Well, that actually tells you the speed rating of your tyres. Tyre speed rating is a code that represents the maximum speed a tyre can handle. In this blog post, we will explain what tyre speed rating is, how it is determined, and why it is important.
What is Tyre Speed Rating?
Tyre speed rating is a code that indicates the maximum speed a tyre can handle. It is represented by a letter from A-Z, except the letter O. Each letter represents a specific speed range, starting from 3 mph to over 186 mph.
For example, ‘R’ indicates a maximum speed of 106 mph, while ‘Y’ indicates a maximum speed of over 186 mph. Therefore, it is important to choose tyres with a speed rating that matches or exceeds your car’s maximum speed.
How is Tyre Speed Rating Determined?
Tyre speed rating is determined by tyre manufacturers. The speed rating is tested in laboratory conditions on a test wheel, and is based on the tyre’s ability to dissipate heat and maintain its shape at different speeds.
Apart from the speed rating, tyres also have a load rating, which indicates the maximum weight the tyre can support. If a tyre’s load rating is exceeded, the tyre may wear out more quickly or suffer from a blowout.
Why is Tyre Speed Rating Important?
Choosing the right tyre speed rating is important for safety and performance. If your car has a higher maximum speed than your tyres’ speed rating, it can affect the tyre’s handling, stability and durability.
Tyres that are under-rated can overheat, wear out quickly, or suffer from a blowout, which can result in a loss of control of the vehicle. On the other hand, if you choose tyres with a higher speed rating than your car needs, it may not make a significant difference in safety or performance.
How to Find Your Car’s Tyre Speed Rating
You can find the tyre speed rating in the owner’s manual or on the sidewall of the tyre. The tyre speed rating is indicated by a letter after the tyre size, such as 205/55R16 V.
It is important to note that replacing tyres with a lower speed rating than the original equipment (OE) tyres is not recommended. If you have upgraded your car’s wheels or tyres, it is important to ensure that the new tyres’ speed rating matches or exceeds the original OE tyres.
Tyre speed rating chart
Speed Rating | mph | Speed rating | mph |
A1 | 3 | K | 68 |
A2 | 6 | L | 75 |
A3 | 9 | M | 81 |
A4 | 12 | N | 87 |
A5 | 16 | P | 93 |
A6 | 19 | Q | 100 |
A7 | 22 | R | 106 |
A8 | 25 | S | 112 |
B | 31 | T | 118 |
C | 37 | U | 124 |
D | 40 | H | 130 |
E | 43 | V | 149 |
F | 50 | W | 168 |
G | 56 | Y | 186 |
J | 62 | (Y) | 186+ |
Need some advice?
If you’re not sure what tyres are the right speed rating for your car or if you have any other questions about car tyres, our helpful team are on hand to help!