This guide covers the extra codes you are most likely to see on a UK car, van or SUV tyre.
XL, Extra Load or Reinforced
These tyres are built to carry a higher load than the standard version of the same size, normally with a higher inflation pressure. If your car came with XL tyres, replace them with XL tyres. Standard-load tyres could be overloaded. See load index explained.
RFT, Run Flat, ROF, ZP and similar
Run-flat tyres carry markings like RFT, Run Flat or manufacturer codes. They have reinforced sidewalls designed to continue to support the vehicle after pressure loss. See run-flat tyre puncture.
M+S and the three-peak mountain snowflake
M+S stands for mud and snow and is a manufacturer's claim about tread design. The three-peak mountain snowflake symbol, shown as a mountain with a snowflake inside, shows the tyre passed a defined snow-grip test. Winter and many all-season tyres carry it. See winter vs all-season tyres.
Directional tyres
Directional tyres have an arrow and the word Rotation on the sidewall. The arrow must point in the direction of forward travel. Fitting a directional tyre the wrong way round reduces water dispersal and grip. A fitter checks the arrows when fitting.
Asymmetric tyres: Inside and Outside
Asymmetric tyres have different tread patterns on each half and are marked Inside and Outside. The mark that says Outside must face away from the car. This matters on every wheel, so check it when new tyres are fitted.
Tubeless and TL
TL indicates a tubeless tyre, standard on modern cars. Tube-type tyres are marked TT and are mostly found on older vehicles, some trailers and some motorbikes.
Tread wear indicators and TWI
The letters TWI, or small triangles around the shoulder, mark the position of tread wear bars set into the grooves. When the tread wears down to these bars, usually at 1.6mm, the tyre has reached the legal limit. See tread depth and the legal limit.
Manufacturer approvals
Some tyres carry a star or letter code, for example a star for BMW fitment or N0 for Porsche, showing the tyre was developed and approved for that maker. They are not legally required but suggest the tyre was tuned for a particular model. A fitter can help you choose a suitable tyre.
Putting it together
When ordering a tyre, mention the size, load index, speed rating and any special markings on your existing tyres. See how to read tyre sizes for the main code and DOT code guide for the date. A mobile technician can then bring the right tyre; see mobile tyre fitting and emergency tyre fitting.
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What the EU tyre label adds
Most new car and van tyres sold in the UK carry a label showing wet grip class, fuel efficiency class and external noise in decibels, and may include icons for snow grip or ice grip. Wet grip is graded from A to E, and it makes a real difference in the distance needed to stop on a wet road. The label does not tell you about durability or dry handling, so treat it as one tool among several when choosing.
Sidewall damage and markings
Markings are moulded into the rubber, so deep scuffs or cuts can obscure them. If you cannot read the size or ratings on a damaged tyre, check the other tyre on the axle, or ask the fitter to read it from the wheel and the vehicle specification. Never guess a size from a damaged tyre: a wrong size can be dangerous.
Reading a sidewall as a whole
Take a typical sidewall: a brand and model name, the size 225/45 R17, the load and speed code 94W, the letters XL, a DOT code with the date, a line showing treadwear and traction grades on some imports, the M+S symbol and an arrow showing rotation. Each element answers a different question: what fits, what it carries, how fast, how old, what season and which way it turns. Work along the sidewall from the size outwards and you can describe any tyre in under a minute.
Which markings really matter when replacing
For most drivers, the essentials are size, load index, speed rating and any XL or run-flat marking. Seasonal and directional marks matter next, because they decide whether the tyre will behave as intended. Brand approval marks are a bonus. If the old tyre is damaged and unreadable, give us your registration and we can check the manufacturer specification.
Frequently Asked Questions
What does XL mean on a tyre?
Extra load. The tyre is built to carry more weight at higher pressure than a standard-load tyre.
What does the snowflake symbol mean?
The tyre passed a defined snow-grip test.
Which way do directional tyres face?
The arrow on the sidewall points the direction of forward rotation.
Can you fit the right tyre for me?
Yes. Call now for a quote on 0800 772 0355.
Related Help
Need help with your tyres now?
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