The motor trade offers a huge range of car tyres covering every requirement and budget. There are tyres designed for performance, fuel economy or off-road handling abilities. So choosing the right tyre can be a confusing business.
Examine a vehicle tyre and you will see a series of letters and numbers moulded into the rubber of the sidewall. These details provide information about the size and diameter of the tyre, the maximum load it can carry, and the speed rating. Testing tyres and giving them an appropriate speed rating ensures that the tyre will not fail under the heat and wear generated by high speed driving, up to the maximum speed allowed by the rating category. The speed rating is indicated by a letter, either on its own or following a number that shows the load rating.
For normal road use, most family cars are fitted with H, certified for speeds of up to 130mph, or V for up to 149mph rated tyres. Smaller models, designed for city driving, may have T rated tyres which are suitable for speeds up to 118mph.
It is rare to see a tyre rated for speeds of less than 100mph, for instance, N, P, or Q, except on classic vehicles. While most cars are unlikely to reach the maximum safe speed for their tyres, fitting a higher specification tyre than the car requires will improve safety margins.
If you are planning to use your car for events like track days, you may need a higher speed rating. Track tyres may be W rated for speeds up to 168mph, Y, for speeds up to 186mph, or Z, for speeds of 150mph and upwards. Bear in mind that track tyres may have less tread than road tyres, making them illegal for road use, so you will need to swap tyres for everyday driving.
Your car’s manual may recommend a make and model of tyre to help you choose one that meets or exceeds the speed rating required for your vehicle’s top speed. You are not obliged to follow the exact specification and you can pick a tyre more suitable for your needs.
Remember, if you are involved in an accident and the speed rating of your tyres isn’t adequate, your insurance policy or motor trade insurance policy could be invalidated. All new tyres sold in Europe now carry a sticker indicating their fuel efficiency and grip in the wet, as well as a noise rating in decibels, measuring how much noise is generated from the tyre at a speed of 50mph.
Many new and used cars come with a space saver type spare wheel to be used as a temporary replacement if you suffer a flat tyre. Tyres on space saver wheels do not have to comply with the EU’s noise, wet grip, and fuel economy regulations, but you should replace the space saver with a new or repaired tyre as soon as possible.
Remember that car tyres should be fitted in pairs, If you have tyres with different grip levels at either side of your vehicle it’s likely to cause problems. For example, if you put a tyre with excellent wet grip on the front driver’s side and keep the old one with much poorer grip on the passenger side, the results could be disastrous.
At 30 mph in dry conditions, you might not notice any difference. But hit some standing water at 60 mph and the car will respond unpredictably, so if you’re replacing one front or rear tyre, you’ll need to replace the other at the same time.