How to Find Your Vehicle’s Tyre Size

Do I fill up with petrol or diesel? Where’s the latch to release the bonnet? You may have to remember these vital details about your vehicle but luckily, you don’t need to remember the size of your tyres.

The long combination of letters and numbers, which relate to the tyre size you should be using, isn’t an easy thing to recall, not to mention where you can actually find it.

But considering you’ll need this information when it comes to purchasing a new tyre or changing a tyre on your vehicle, it’s handy to keep a note of!

In this article, we’ve shared the three places in which you can find your vehicle’s tyre size, along with the meaning behind each letter and number in order for you to purchase new tyres that are suitable for your car.

What size are my tyres?

If you’re looking to find the tyre size of your vehicle, there are three places to look. These are:

  • Car manual: Your manufacturer’s handbook will have a section about the vehicle’s tyres, including the tyre sizes
  • Driver’s side door: Beneath the driver’s door, there is often a label which shows key information about the vehicle. You may be able to find the right size here
  • Current tyres: If your current tyres are not too old and worn, you may be able to see their size printed on them.

Reading tyre sizes

Once you’ve located your tyre sizes, you’ll see that the long combination of letters and numbers all signify different areas of the tyre:

A typical car tyre size looks like this: 123/45R 12 91 H.

123: Means the width of the tyre in millimetres (mm).

45: Signifies the ratio or profile of the tyres. This is the calculation of the sidewall of the tyre expressed as a percentage of the width of the tyre. In this example, an aspect ratio of 45 means that the profile of the tyre is 45% of the tyre’s width.

Letter R: Indicates the type of car tyre that it is. The letter R shows that this example is a radial tyre, which means that the tyre has additional strength as the cord piles are positioned at a 90-degree angle.

12: Is the diameter of the wheel rim in inches (in).

91: Shows the load index. This indicates the maximum weight capability for a tyre. In this case, 91 indicates a load capacity of 615kg. It’s not advised to have tyres with a lower load index than the manufacturer recommends for your vehicle, or to combine different tyre types.

H: This letter shows the maximum speed that the tyre can withstand. For example, if your tyre has a letter Q here, the maximum speed would be 99mph. If it is the letter Y, the maximum speed for that particular tyre would be 186mph.

As you can see, by locating the place in which you can find your tyre size, you’re also able to understand what the string of letters and numbers on your tyre mean. From the maximum speed and weight that they’re able to withstand, you’re able to get more out of your vehicle by knowing the limits of your tyres.

Comments are closed.