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Are you looking for Tyres Size for your vehicle?

You may have noticed that different car makes and models require varying tyre sizes.

Mounting tyres of the right size is crucial to your vehicle’s safety and performance; experimenting with this factor can affect a tyre’s longevity and wear, as well as the car’s safety.

That’s why we at Garth Tyre & Auto Services always recommend our customers to refer to the car manufacturer’s manual when they buy car tyres Cardiff; you can also find this information at the sidewall of your vehicle’s tyre.

However, most of our patrons do not clearly understand what such alphanumeric code at the sidewall of their vehicle tyre signifies; if you are uncertain about its meaning, read along!

Understanding tyre sizes

The format for tyre size is similar across all modern tyres. Take an example- 235/40 R18 95 V; each of these numbers and letters– 235, 40, R, 18, 95, V, signify a particular tyre feature, complementing the vehicle’s overall performance.

Let’s decipher these numbers and letters to understand better, so you can buy new car tyres Cardiff more soundly:


The first three digits denote the tyre width in millimetres, which is 235mm in this code.

Aspect ratio

The next two digits– 4 and 0 in the example mentioned above – represent the height of a tyre from the tread’s base to the rim, per cent of the tread width; the tyre’s height here is 40% of 235 mm.

Construction type

This letter denotes the construction type of your car tyres Cardiff. Most tyres today carry the alphabet R, signifying radial tyres. It implies the tyre has a radial ply construction; other construction types include D, which stands for diagonal, and B for belted.

Rim diameter

The following two digits in the tyre size format represent the wheel rim’s diameter. If you plan to buy wheels for existing tyres Cardiff, you will need to buy them as per this measurement.

Load index

The next two-digit number shows the load index; it can also be a three-digit number. Also known as load rating, it is an industry-standard figure denoting the maximum weight a single tyre can carry when properly inflated. For instance, if your car tyre shows a load index of 88, its maximum load capacity is 600 kg.

Speed rating

The alphabet at the end stands for speed rating. It signifies the maximum speed at which the tyre can be operable safely, given it is correctly inflated and fitted. The highest speed rating is Y, which denotes a maximum speed of 186 mph.

At our facility in Cardiff, we stock tyres of all sizes under the sun. When you buy car tyres Cardiff online with Garth Tyre & Auto Services, enter the tyre size you need to view our catalogue. We provide next-day fitting at our garage, so you won’t have to wait to enjoy your new car tyres. So, get them today with us!