How To Find Speed Rating On Tires

Speed rating on a tyre sidewall

Where exercise I find the tyre speed rating?

The speed rating is displayed on the tyre's sidewall, after the load rating. In this example, the automobile'due south speed rating is W, which indicates that it has been legally canonical for utilize upwards to 168 mph.

How is the speed rating calculated?

Speed ratings are based on laboratory tests in which the tyre is run at 6.2 mph steps, in ten minute increments, until the required speed has been met. To receive its rating it must demonstrate that it can sustain a particular speed when tested with simulated loads.

The speed rating is represented by a letter – A being the lowest and Y being the highest. Every bit you will see on the nautical chart below, there are some anomalies every bit machine manufacturers accept increases the speeds of their vehicles and speed ratings take been introduced to lucifer them.

Most mutual tyre speed ratings, speeds and vehicle usage

Are speed ratings only most speed?

No. They're likewise near ride comfort, traction, tread wear and cornering ability. A higher speed rating more often than not offers amend grip and stopping ability, but it may have a lower tread life and reduced operation in cold conditions. That's why 5, Z, W and Y-rated tyres are normally better suited to high operation vehicles in warmer climates.

You can increase the speed rating of your vehicle'southward tyres for improved operation, but can never decrease it without reducing the vehicle's meridian speed to that of the lower speed rating selected.

Tin can I mix speed ratings on my vehicles tyres?

If you are going to mix speed ratings, which we don't recommend, make sure the lower rated tyres are on the front end beam, regardless of whether your vehicle is front-, rear- or four-wheel drive. This is to preclude a potential oversteer scenario. Acquit in mind that all tyres must be advisable for the vehicle and you should drive no faster than your lowest rated tyres.

We would e'er recommend that the same size and type of tyre, with the same speed ratings, are fitted on all tyres.