How do you read a tyre label? All-important information for motorists

Are you confused by the strange series of numbers and letters on your tyres? These elements are important for all drivers because they contain essential information: tyre width, load index, speed rating etc. But what exactly do the descriptions mean? We explain how to read a tyre label in this article, so you can quickly find the right tyre model for your car.
How do you read a tyre label? All-important information for motorists

Why is it so important to be able to read a tyre label?

Whether it’s simply for safety purposes or to comply with the relevant legal requirements: Knowing how to decipher those elements that piece together clearly marked sequences on the sidewall of every tyre is essential for you.

More importantly, these even use classifications to list their features, allowing you to make the right choice when you need to purchase a new set of tyres for your vehicle. Plus, even though you can read the information on your tyre sidewall, it’s still not always easy to locate or identify the best kind of tyres needed for summer or winter driving.

Essential information for all tyres

The dimensions of your tyre

The width of a tyre (measured from sidewall to sidewall) is always expressed in millimetres. This measurement is indicated on the tyre’s sidewall and separated from the following aspect ratio with a backslash (“/”) symbol. This latter metric is expressed as a percentage and corresponds to the ratio between the cross-section of your tyre and its width. The height of your tyre is always given as a percentage value, too. For example, if the aspect ratio reads 65, this means that the tyre’s height is 65% of its width. The lower the height of the tyre’s sidewall (and the lower the ratio figure), the better the grip — but this may come at the expense of some driving comfort.

The structure and diametre of your tyre

The second section of information may appear in the following format: R18. In this example, the letter “R” refers to the structure of your tyre — in this case, it denotes a radial tyre. It is the most common and almost universal structure you will encounter among modern tyre models. You may also occasionally come across the letter “D”, indicating a diagonal tyre structure. The number that follows this letter always indicates the tyre’s diameter. This dimension is measured in inches (18 inches in our example), which corresponds to the inner diameter of the wheel rim.

Load index and speed rating

The last number you will find on each tyre denotes the load index of that tyre. However, this number does not supply direct information regarding the maximum load weight that your tyre can handle: it refers to the load index rating, which will reveal the maximum load capacity (sometimes called: carrying capacity) of a tyre in kilograms when consulted. For instance, a tyre bearing a load index rating of 91 should be capable of carrying a maximum load of 615 kg (see the tyre load index chart).

Finally, when correctly inflated, a capital letter indicates the speed rating of any tyre. The letter corresponds to a specific value summarised in the speed index table. For instance, a tyre bearing a speed rating of “V” can handle a maximum speed of up to 240 kph. The best high-speed performance tyres are marked with “ZR”. These tyres are suitable for driving at a top speed of over 240 kph (see the speed rating chart).

A good tip: When changing tyres, you can opt for tyre models with a higher speed rating than what your original tyres show on the label. However, for safety reasons, you should never consider fitting replacement tyres with a speed rating lower than that of the original tyres designed for your particular vehicle.

Winter markings

This seasonal marking is located just after the speed rating on a tyre. It is either written as “M + S” (which means: tested for driving safety on mud and snow) or else consists of a snowflake enclosed by three stylised mountain peaks (which means: tested for driving safety under extreme winter conditions).

Specific labelling on Michelin tyres

Safety, durability, fuel economy, comfort and sheer driving pleasure: Michelin constantly offers new, exciting innovations through the continuous development of increasingly sophisticated high-performance tyres. You can recognise Michelin-specific technology indications as follows:

  • GREEN X: Excellent level of energy-efficient performance, offering better traction and extended service life,
  • ZP (Zero Pressure): With no air in the tyre or even after sustaining a flat, you can continue driving on your tyres for 80 km at a speed of up to 80 kph (50 miles at 55 mph),
  • SELFSEAL: Your tyre will effectively seal itself in the event of a crack or a flat,
  • Acoustic: Helps to significantly reduce the noise level created by the friction between your tyres and the road.

Now you know all about the markings you will likely encounter on Michelin tyres. This information can help you choose the ideal tyre model for your car; in terms of both its dimensions and integrated technologies.

Tyre load index chart

Speed rating chart