Tyre speed rating is a code that represents the maximum safe speed a tyre can sustain under specific load conditions. It indicates the tyre's ability to dissipate heat and maintain stability at higher speeds. The speed rating is denoted by a letter, such as "H" or "V," which corresponds to a specific speed range. Choosing tyres with appropriate speed ratings is essential to ensure safe and reliable performance. Consult your vehicle's manual or a tyre professional to determine the recommended speed rating for your specific vehicle and driving needs.
Speed Category Symbol | Speed (km/h) | Speed Category Symbol | Speed (km/h) | Speed Category Symbol | Speed (km/h) |
---|---|---|---|---|---|
A1 | 5 | E | 70 | S | 180 |
A2 | 10 | F | 80 | T | 190 |
A3 | 15 | G | 90 | U | 200 |
A4 | 20 | J | 100 | H | 210 |
A5 | 25 | K | 110 | V | 240 |
A6 | 30 | L | 120 | W | 270 |
A7 | 35 | M | 130 | Y | 300 |
A8 | 40 | N | 140 | Z | *Over 240 |
B | 50 | P | 150 | ||
C | 60 | Q | 160 | ||
D | 65 | R | 170 |
In Australia, tyre speed ratings typically range from N to Y, with each symbol representing a corresponding maximum speed in kilometers per hour (km/h). The ratings are determined through various tests conducted by tyre manufacturers, including the speed test. It's important to note that the recommended speed for safe and optimal performance may be lower than the maximum speed indicated by the rating. It's crucial to adhere to the recommended speeds provided by the vehicle manufacturer and consider factors such as road conditions and load to ensure a safe and comfortable driving experience.
*Consult tyre manufacturer for Speed and Load Capacity
When the letters “ZR” are included in the tyre size and followed by a service description, the tyre speed category is that included by the service description.
Service Description Examples: | |
---|---|
Tyre Description | Maximum Speed Capacity |
225/55R 17 97W | 270kph |
225/55ZR 17 97W | 270kph |
255/40R 17 94W | 270kph |
255/40ZR 17 (94)* | Over 240kph* |
*Only tyres V, W or Y are included in this category.
The tyre manufacturer must be consulted to ascertain the tyre’s maximum speed capability when the tyre has a “ZR” symbol and no service description. The “ZR” symbol must appear in the tyre size designation for tyres having a maximum speed capability of over 300kph.
Book in a Vehicle Service at a JAX Tyres & Auto Near Me!
The tyre speed rating is the maximum speed tyres can safely carry a load for a sustained amount of time in ideal conditions. This includes the original weight of your vehicle and whatever is in it.
Your actual speed capacity may be less than the tyre’s rating. The tyre is tested in tightly controlled lab conditions. Outside factors may affect the maximum speed the tyres can handle and limit the tyre’s maximum safe speed:
- Tyre condition
- Inflation level
Extra cargo or weight - Road surfaces
- Weather
Tyres with a higher speed rating are usually made with softer rubber compounds and stiffer construction. This leads them towards better cornering, stopping power and steering abilities.
You can find your tyre speed limit moulded on the tyre sidewall, signified by a
letter or two, usually after the load index number. Typically, it can be found in the owner's manual and driver’s side door jamb.
The letter is associated with the tyre's maximum speed capability when operating at its maximum load-carrying capacity.
If a tyre is marked with ‘L’ then it can be safely operated to a maximum speed of 120km/h
There is no problem installing a higher-speed-rated tyre on your vehicle.
Installing it can improve your cornering response, stopping power and steering abilities. You just can’t drive with tyres that are lower than the recommended speed rating.
You should look at your speed rating and your load rating together.
If you have tyres with different speed ratings, the limit on the lowest-rated tyre is your fastest capability.
It is not recommended that you mix and match tyres that have different speed
ratings. If you are thinking of replacing your tyres, speed-rated tyres should be replaced in sets of four.
If you have tyres with different speed ratings, the limit on the lowest-rated tyre is your fastest capability.