Car tyres can have different speed ratings depending on how they were made and designed. Different tyres for the same car may have different properties and it is important to understand the codes that manufacturers use when making a specific tyre. Tyre speed rating W is usually associated with high performance or exotic cars.
What Does “W” Speed Rating W Represent?
The speed rating represents the maximum speed recommended for the tyre. W means that the tyre supports a maximum speed of 168 mph or 270 km/h. There are only two other speed ratings that support higher speeds but 11 more that are limited to lower speeds. This puts the W speed rating close to the top. Such tyres are quite expensive and can only be found in certain sizes.
What Makes a “W” Speed Rating Tyre Different?
As these tyres are designed for high-performance cars, they are subject to higher centrifugal forces. This means that the same structure and rubber compound used for an H rated tyre will not be able to survive at higher speeds. The risk of tyre explosion increases.
To make a W rated tyre, different rubber compounds are used and more reinforcement is added. These tyres use a softer rubber to allow them to have a better grip. At higher speeds, if the rubber compound is not soft enough, the car will slide on the road as if it is running on ice. W rated tyres are softer, have different tread patterns and improved grip.
It is worth noting that W rated tyres wear out much faster. As the rubber compound on the surface of the tyre is softer, it will get scraped off faster trough repeated breaking than a regular set of tyres with a lower speed rating.
Lastly, such tyres that can support speeds as high as 168 mph or 270 km/h are quite expensive. The materials used are made to improve driving stability in the detriment of ride quality. Also because they are made for high-performance cars, they are rarely available in smaller 16 or 17-inch sizes. Manufacturers tend to make them for larger rims and sizes that are typical for exotic or sports cars.
Planning on Fitting W Rated Tyres On You Car?
If your car has a manufacturer recommended tyre speed rating W, it is better to stick with that recommendation. Manufacturers test out their cars in different combinations of engines and tyres, depending on how the vehicle was designed to be used. Based on their tests, they recommend a particular type of tyre that provides an optima ride quality, stability, braking power and grip. Using a different type of tyre may result in undesired car behaviour.
Cars that have a tyre speed rating recommendation that is lower, should always be fitted with that type of tyre. Using higher speed rating tyres will affect ride quality, cause accelerated wear to the shocks and springs and may even affect fuel efficiency. However, they may improve braking performance and grip but will wear out much faster. It is always recommended to check with an expert and see what tyres are recommended for a particular car and if some upgrades may be available that could improve performance.