The importance of having the correct tyres

Those clever ‘value my car’ services can take all sorts of things into account when telling you what a car is worth. But we don’t know of any that ask you about the state of the tyres. Which is funny, when you think about it because tyres are one of the most important things on any vehicle.

As the only point of contact between you and the road surface, tyres are vital for safety. And given that they can also be very expensive, it’s important to not only understand whether they’re in good condition but also that they are of the correct and appropriate type for the car they’re fitted to.

So, what do you need to know about tyres to make sure they’re correct? This handy list is here to help.

Sizing

Probably the most important thing is that the tyres fitted to a vehicle are the correct size. If they aren’t it can impact everything from the speed shown on the speedometer to the amount of grip you have in the corners and even how much fuel you use.

To find out the correct tyre size for your car you can look in the owner’s manual – or go to a tyre supplier, such as Halfords, and use the number plate checker. The format for modern tyre sizing is universal for all brands, and can then be compared to what’s written on the tyres fitted to the vehicle. An example of this format is 195/55 R16 87V.

In order, this deals with the width/sidewall height, the construction and wheel size, and finally the load rating and speed rating. It’s worth noting that sometimes the sizing will be different on the front and rear axles – but you should always fit the same size of tyre on either side of the car.

Load rating

This tells you the tyre is suitable for the weight of the vehicle and what that vehicle is going to be carrying. In the example above, 87 is code for a load rating of 615kg.

If the load rating is lower than it should be, you risk the tyre failing as you drive. If the load rating is unnecessarily high you may find it makes the car uncomfortable.

Speed rating

The V in the example above means that the tyre is rated for speeds up to 149mph. That may seem irrelevant in the UK where the maximum speed limit is 70mph, but having the correct speed rating means a tyre is suitable for the kinds of stresses the car it is fitted is designed to endure.

Fit too low a speed rating to a high-performance vehicle and, again, you risk the tyre failing unexpectedly.

Different types of tyres

Similar to the above, it’s probably not wise to fit a budget brand of tyre to a high-performance car, and you’ll find that even the most well-known tyre brands make a range of products for different kinds of uses. Putting it another way, it’s also probably not a good idea to put a sporty tyre on a vehicle that’s often driven on rough terrain or very slippery surfaces. Different types of vehicles require different types of tyres.

You may also find that some car manufacturers fit ‘run flat’ tyres as standard. It’s probably wise to fit a similar type of tyre when it comes to replacement time.

Finally, it’s worth knowing that some car makers have tyres made to their specific standards. So even tyres that have the same brand and model name might be different if originally specified for a Mercedes-Benz. While any equivalent tyre should be a suitable substitute, to maintain a vehicle exactly as its maker intended you may wish to seek out these specially developed tyres – some buyers will certainly be looking for them when considering a second-hand purchase.