Tyre speed rating explained
Understanding tyre data can seem confusing at the best of times but, at Protyre, we are here to help! The code found on the sidewall of a tyre gives quite a lot of information, including the diameter, height, width of the wheel, and the load index rating. The single letter at the end of the code represents the tyres speed rating. For example, if the code is 205/55R/16/91V then it is the V that is the speed rating.
So, what is tyre speed rating?
Essentially the speed rating of a tyre is the maximum speed that it can safely tolerate – if running at the approved load capacity. The rating is given as a letter and each letter represents a different speed. This rating exists to ensure the safety of your tyres.
Speed ratings range from L to (Y). The system is based on the European use of kilometres, which is why the ratings in mph seem as though they increase in unusual increments. The speed ratings are established by engineers who run the tyres in ten-minute increments until the desired speed has been met. In imperial terms, the difference between each letter is approximately 6mph.
The speed ratings by letter are outlined below:
L = 75mph/120kmh
M = 81mph/130kmh
N = 87mph/140kmh
P = 93mph/150kmh
Q = 99mph/160kmh
R = 106mph/170kmh
S = 112mph/180kmh
T = 118mph/190kmh
U = 124mph/200kmh
H = 130mph/210kmh
V = 149mph/240kmh
Z = 149mph+/240kmh+
W = 168mph/270kmh
Y = 186mph/300kmh
(Y) = 186mph+/300kmh+
V, Z, W, Y and (Y) are for sports cars. L rated tyres are primarily for off-road and light trucks. Q is primarily for winter 4x4s. R is primarily for heavy-duty light trucks. S and T are primarily for family saloons and vans. U is primarily for saloons and coupes. H is primarily for sports saloons and coupes.
Tyres with larger diameters often also have a higher speed rating because they are intended for use on higher-performance cars so need to be able to handle higher speeds.
For most modern cars, the tyre rating is not the same as the maximum speed the vehicle is capable of. For example, most family cars will have a tyre speed rating that is higher than the car’s maximum speed. This is mainly for safety reasons and so that the performance of the tyres always exceeds the maximum performance of the car. A higher speed rating means that the tyre is able to cope with acceleration, braking, and high-speed cornering.
Why are speed ratings important?
When travelling at higher speeds your wheels turn faster and more heat is subsequently generated. It is important, therefore, that the chosen tyres can cope with this.
Speed ratings are not exclusively about speed – they are also about ride comfort, tread wear, traction, and cornering ability. A tyre with a higher speed rating will give better grip and stopping power but may not last as long and may not perform as well in cold weather/winter conditions. V, Z, W, and Y-rated tyres, therefore, tend to be better suited to high-performance vehicles driven in warmer climates.
Can I fit tyres with a higher speed rating?
Yes, this is fine. If changing tyres, there are no issues with fitting models that have a higher speed rating than your current ones.
Can I fit tyres with a lower speed rating?
No, you should NEVER do this. Using a tyre with too low a speed rating for the car increases the risk of tyre failure at high speeds. Also, doing this can potentially invalidate your insurance.
The local garage you can trust
All Protyre garages are staffed by qualified fitters and our tyre professionals have years of experience to call on. Our garages stock a range of tyres to suit all budgets, including options from well-known manufacturers such as Pirelli, Goodyear, Falken, Sumitomo, and Bridgestone.
Our website also has an easy-to-use tyre finder tool – click the “Buy Tyres” button below and simply enter your registration number into the search box. You will then be shown a range of options available at different price points together with some useful details about each tyre, such as fuel economy rating, wet weather grip level, and noise levels.
If you would like an experienced mechanic to give your tyres the once over (or replace them), why not give your nearest Protyre garage a call to arrange an appointment? We offer free tyre checks and a number of other vital free safety checks. To find your nearest Protyre garage, click the button below and enter your postcode into our search box. You can also book a tyre check online if you prefer.