For those unfamiliar with tyre markings and labels, buying a new set of car tyres can feel like trying to crack a code. Luckily for you, here at LK Performance we know our runflats from our radials, and we can help you find the right car tyres and winter tyres for your vehicle with our handy guide to different tyre markings and their meanings.

First up, what do tyre labels mean?

When car tyres are purchased new, they should have a familiar-looking label stuck to them, rather like the ones you’d expect to find on a new fridge or washing machine. These labels, required by EU legislation, offer information on the individual properties of the tyre and will help you to compare it to others from different manufacturers.  

Here’s an overview of the most important information that’s displayed on a tyre label. 

Fuel economy

An ‘A’ rated tyre offers better fuel efficiency than a ‘G’ rated one. How much exactly? Over the lifespan of the tyres, approximately 80 litres of fuel.

Braking efficiency in wet conditions

Here’s a pretty sobering fact: an ‘A’ rated tyre will stop a full 18m shorter than a ‘G’ rated one when travelling at 50mph.

External noise levels

This is shown on the label as a wave graphic; three waves mean the tyre is as noisy as it gets, while one wave means it's quieter than average. 

Additional considerations to keep in mind

It’s also worth considering tyre longevity, road handling and dry braking capabilities, all of which will be on the label, before deciding on a purchase.

What do tyre markings mean?

Now let’s get to the markings on the sidewall of the tyre itself. 

Apart from displaying the brand and model of tyre, the letters and numbers embossed on the sidewall also establish their fitting type, age, dimensions, composition and capabilities. In short, they’re pretty important!

However, these tyre markings aren’t as straightforward as they may first appear, so you would be forgiven for being a little confused. We’re here to make things simple by breaking down each element, step by step. 

If we were to use the tyre code P185 65 R15 88 H as an example, it would break down as follows:

• P denotes that it’s for a passenger-bearing vehicle.
• 185 is the tyre width expressed in mm.
• 65 is the tyre sidewall height or profile, but as a percentage of its width, rather than an actual measurement.
• R denotes a ‘radial’ tyre structure, as opposed to cross-ply. It’s important not to mix these two up on a car and have all of them the same.
• 15 is the diameter of the wheel rim, or ‘rim size’, but in inches as opposed to mm, confusingly.
• H is the speed rating, which must at least match or exceed the top speed of the vehicle.

All of this may seem a little convoluted, but this info is in your car handbook and can also be found very easily by tapping your car make and model into LK Performance’s handy car tyre search function.

Standard car tyre speed ratings tend to fall into eight given categories:

• S up to 112mph
• T up to 118mph
• U up to 125mph
• H up to 130mph
• V up to 149mph
• W up to 168mph
• Y up to 186mph
• ZR over 149mph

Again, the higher the rating, the more your car tyres will cost. Tyres for a Bugatti Veyron for example, are around £5000 each!

Other crucial tyre markings explained​

Manufacturer’s date stamp

There are a couple of other numbers that are worth knowing about. First up, the manufacturer's date stamp. You may be buying new-looking, unworn tyres that are in fact quite old, having sat in a warehouse for any number of years. By studying the date stamp, you can make sure you’re getting your money’s worth. 

Run flat tyre labels

In addition there are another set of markings which are relatively new, and these are the letters indicating ‘run flat’ tyres. These letters are ROF, RunFL, DSST and RFT.

This means that should you get a puncture, the tyre is safe to run flat for a full 50 miles, without shredding and allowing the wheel itself to sustain damage - depending on the kind of blow-out you suffered in the first place, of course.

As with cross-ply, it’s important that run flat tyres are not added as individual tyres, but as a whole set, as they could adversely affect the car’s handling. 

It’s also advisable that some sort of tyre pressure monitoring system is utilised in conjunction with these tyres, just to ensure you’re aware if you do get a loss of pressure for any reason.

Mounting direction

Finally, it’s quite common these days that tyres are asymmetric in their construction and need to be fitted a certain way around, with one side on the outside of the car. 

This is particularly important when you consider the front steered wheels, which take substantially different loads under stress. Always make sure your new tyres are fitted the correct way round before you take them for a spin.