Understanding Tyre Labels and Markings

Reading tyre labels and markings is crucial for selecting the right tyres for your vehicle. It is also useful to know how fuel efficient they are, what level of wet grip they provide or how much noise they produce which is where understanding EU tyre labels is useful.

However, this information is presented as alphanumeric codes and symbols on the tyre sidewall which can be confusing.

Our guide will teach you how to read everything including the tyre size, aspect ratio, construction, diameter, speed and weight ratings.

How to Read Tyre Size and Ratings

An example of tyre sidewall marking is 255/35 R 20 (96Y). Each section represents a different aspect of the tyre and consists of the following:

Tyre Width

The first set of numbers on the tyre reading is the width of the tyre in mm. In this case, the tyre width would be 255mm.

Tyre Aspect Ratio

The set of numbers straight after the tyre width refers to the height of the tyre wall (or aspect ratio) which is a percentage of the width. In this instance, 35 would have a height equal to 35% of the tyre’s width. This number is also often referred to as the tyre profile.

Tyre Construction

Following the tyre profile, you will see a letter. In this example, it is marked R which represents the tyre construction . R stands for radial and almost all tyres manufactured these days are radial tyres. Less common tyre constructions include B (bias belt) and D (diagonal).

• Radial tyres have a sidewall running straight up and down and are made of a single layer of steel cord piles running at a 90-degree angle to the centreline of the tyre.
• Bias belt tyres are pneumatic tyres with a diagonal cross ply casing and a reinforced belt under the tread.
• Diagnoal tyres use layers of nylon cords that run diagnolly across the tyre to create a crisscross pattern.

Tyre Diameter

The next set of numbers after the tyre construction letter represents the inner diameter of the tyre rim in inches. The diameter of the rim is 20 inches in this example.

Tyre Maximum Weight

The last set of numbers represents the load rating which is the maximum weight the tyre can carry in kg, assuming the tyre is correctly inflated. Here it would be 96kg.

Tyre Speed Rating

The final letter of the tyre code represents a speed rating which is the maximum speed that the handle while correctly inflated and under load. The letter displayed will vary, often between Q and Y. In this example, Y means that the maximum speed is 186mph.

Other letters are documented in this table:

Code	mph	Code	mph
Q	100	V	149
R	106	V	Over 149
S	112	W	168
T	118	(W)	168
U	124	Y	186
H	130	(Y)	Over 186

So, the tyre sidewall marking of 255/35 R 20 (96Y) is dissected as:

255: Tyre’s width in millimetres

35: Sidewall height as a percentage of the tyre’s width

R: Indicates that the tyre is radial

20: The wheel rim diameter in inches

96: The load index rating

Y: The speed rating

There are other markings on a tyre sidewall which include the following:

Brand Name

The brand that manufactured the tyre will be clearly displayed and is often the largest piece of writing on the tyre.

Date of Manufacture

The four digit number you’ll find on your tyre sidewall represents the date your tyre was manufactured. Sometimes it is displayed as something similar to this DOTXXXXXXXX2921. The first two numbers of the last four, refer to the week your tyre was manufactured and the last two numbers refer to the year. For example, if the marking on your tyre reads 1919, this means the tyre was made in the 25th week of the year 2019. This allows you to identify the age of your tyre which is important once tyres are ten years old, they are illegal to drive on.

Tread Wear Indicators

Your tyre may wear out before ten years. To check this, you need to check your tyre tread indicators. When the tread on your tyre is worn down to the same level as the wear indicators, your tyre has reached the minimum tread depth level.

Rather than on the sidewall, tread wear indicators are situated in the grooves of the tyre and may be in the form of the letters ‘TWI’, a small image or a logo. The markings will only be visible when the tyre tread is close to approaching the legal minimum of 1.6mm.

You can also check this with a 20p coin by placing it into the main tread grooves of your tyre. If the outer band of the 20p coin is obscured when it is inserted, then your tread is below the legal limit and your tyre needs replacing.

Country of Manufacture

Where your tyre was manufactured will also be indicated by the writing on the sidewall.

Type of Tyre

Your tyre will feature the word ‘tubeless’ or ‘tube type’.

The word ‘tubeless’ means your tyre does not require an inner tube.

The word ‘tube type’ indicates the tyre requires to be fitted with a tube.

Reinforced Tyres

Reinforced tyres are tyres that have been designed to handle extra weight and will be marked to indicate they have been reinforced. This marking does vary between manufacturers but will likely be shown as EXL, EXL, RF, REINF, or RFD.

Run Flat Tyres

With run flat tyres, you can drive for a short amount of time if you lose pressure or have a puncture, giving you a chance to drive to a safe place. Run flats are designed to last without pressure for approximately 50 miles but should not be driven on faster than 50mph. If the tyres have been run flat, you will need to replace them. Again, the markings for run flat tyres can vary between manufacturers but will often be shown as ROF, EMT, RFT, ZP, SSR or DSST.

Homologation

Homologation is a term for the whole vehicle approval process. An OE marking embossed into the sidewall of a tyre indicates which car a tyre has been designed for and it will also indicate that the tyre meets the vehicle’s manufacturer’s standards.

For example, BMW and Mini have a star symbol, Audi is AO, Porsche has symbols of n0, n1 and n2 and Mercedes is MO. Below is a table of manufacturer’s OE homologation markings:

Manufacturer	OE Markings
Audi	AO, AO+, RO1, RO2
Aston Martin	AM
Bentley	B
BMW/Mini	*,/td>
Ferrari	K1, K2, K3
Jeep	JP
Jaguar	J
Lamborghini	L
Land Rover	LR
Lotus	LS
Maserati	MGT
McLaren	MC
Mercedes	MO, MOE, MO1, MO-S, MOE-S, MO-P
Porsche	N0, N1, N2, N3, N4, N5, N6, NF0
Tesla	T0, T1, T2
Volvo	VOL

Electric Vehicle Tyres

On electric vehicle (EV) tyres you may see the HL load index code at the beginning of the tyre marking. These letters are found on electric vehicle tyres and indicate that the tyre can handle a higher load index. The HL marking was introduced in 2021, and more tyre brands are expanding to include these in their range.

European ECE Type Approval

If your tyre has an E with a digit following it, this means your tyre has been tested and passed European safety standards. The digit that follows the E corresponds to the country in which the tyre was approved. E11 would mean your tyre has been approved in the United Kingdom.

EU Tyre Labels

EU tyre labels provide clear information on the safety and environmental characteristics of a tyre and these labels are split into three categories: fuel efficiency, wet grip and noise. The information on them changed in 2021 to also include tyre performance in snow and ice.

Fuel Efficiency

Knowing the fuel efficiency will allow you to save money on fuel costs in the long run. Fuel efficiency is calculated by the tyre’s rolling resistance and is rated between A to E. A high fuel efficiency rating also contributes to lower CO2 emissions meaning the tyres will be better for the environment.

• A: The most fuel-efficient tyres, offering up to 7.5% better fuel economy than grade G tyres when fitted as a set of four (per the European Commission's impact assessment SEC (2008) 2860).


• B: Highly fuel-efficient, with performance slightly below grade A tyres.


• C: Above-average fuel efficiency but noticeably less efficient than grade A tyres.


• D: Not used in labels before May 2021. After May 2021, grade E tyres were reclassified as grade D.


• E: Below average fuel efficiency. Some tyres in this category, such as those designed for enhanced grip (e.g., sports or winter tyres), may prioritise performance over rolling resistance. Reclassified as grade D after May 2021.


• F: Poor fuel efficiency, up to 6% worse than grade A tyres. Similar to grade E, some tyres in this category may trade rolling resistance for grip. Reclassified as grade E after May 2021.


• G: The least fuel-efficient, using approximately 7.5% more fuel than grade A tyres when fitted as a set of four. However, specific designs like sports or winter tyres may justify higher rolling resistance. Reclassified as grade E after May 2021 (per SEC (2008) 2860).

Wet Grip Ratings

The wet grip rating indicates the tyre’s wet braking performance. The rating shows how much the tyre grips the road in wet and rainy conditions with the higher the wet grip rating, the shorter the braking distance.

The wet grip grating is iconised with a tyre, water droplets and a rain cloud and is again rated between A and E.

• A: Top-rated tyres for wet braking, stopping up to 18 metres shorter than grade G tyres on wet roads at 50 mph (tested per regulation EC1222/2009).


• B: Excellent wet-braking performance, stopping 3 meters further than grade A tyres but 15 meters shorter than grade G tyres.


• C: Above-average wet-braking performance, stopping 6 meters farther than grade A tyres but 12 meters shorter than grade G tyres.


• D: Unused on labels before May 2021. After May 2021, tyres previously graded E are reclassified as grade D.


• E: Below-average wet-braking performance, stopping 9 meters further than grade A tyres but 9 meters shorter than grade G tyres. Reclassified as grade D after May 2021.


• F: Poor wet-braking performance, stopping 12 meters further than grade A tyres but 6 meters shorter than grade G tyres. Reclassified as grade E after May 2021.


• G: The least effective in wet braking, stopping up to 18 meters further than grade A tyres. Reclassified as grade E after May 2021 (tested per regulation EC1222/2009).

Noise Ratings

Previously indicated using a soundwave pictogram, this was replaced with a letter-based grading system in 2021.

Noise ratings consider the amount of external noise the tyre makes. For those who are environmentally conscious, a low noise rating is important as it reduces the impact of your driving on those around you. The noise level of the tyre is measured in decibels and can be found on the bottom of the label with a rating of A, B or C. Around 67-71dB is considered as a low noise level.

• A: Below EU noise limits.


• B: Meets EU noise limits.


• C: At least 3dB’s above EU noise limit.

Snow and Ice

If your tyres perform well in snowy and icy conditions, they will have a pictogram on them also known as the 3 Peak Mountain Snowflake (3PMSF).

Another symbol that indicates a tyre is suitable for winter driving conditions is the M+S symbol which stands for ‘mud and snow’. However, this is not protected and is not an industry standard like 3PMSF so does not guarantee adequate grip.

Final Thoughts

Now that you understand how to read tire markings, you’ll be better equipped to choose the right tyres for both you and your car when the time comes for a replacement. This knowledge will allow your vehicle to be as safe as possible whilst retaining good performance and efficiency.