Tyres, like other parts of a vehicle, have their limits from load or weight index to speed limit. The speed rating of a tyre is an indication of the maximum speed in which the tyre is capable of attaining in ideal conditions. The tyre speed ratings are standards that are set by the tyre manufacturers, and this is based on testing.
Handy Hint - If you are shopping for tyres online, some websites will display the speed rating before you purchase them, some will not show you unless requested. So make it a point to Always Ask and shop only from reliable online tyre sellers.
Always use tyres with a speed rating that is recommended by your car manufacturer, although it is still ok to use a tyre with a higher speed rating. For example, instead of using an H-rated tyre on the Audi A3, you could make use of a V-rated tyre with a speed rating of 350 kph.
What is Tyre Speed Rating?
Speed rating ensures a vehicle's tyres align with its maximum speed capability. Using the Audi in the previous example, the H speed rating is 210 kilometres per hour (130 mph) under optimal conditions. Please note, this does not give you the audacity to reach this maximum whenever you drive your car, always observe the proper speed limit as declared by your State's law.
This post will open your eyes to the various speed ratings that exist and what each of them indicates.
H Speed Rating
This is the first speed rating on the list. An H speed rating indicates that the tyre is approved for speeds not more than 210 km/h (130 mph) under optimal conditions. Tyres in this category are at the low end of the performance tyre speed ratings and are suitable for most standard family vehicles.
W Speed Rating
The W speed rating indicates that the tyre is approved for speeds up to 270 km/h (168 mph) under ideal conditions. Tyres rated as W land at the performance end of the tyre speed rating spectrum. W speed rated tyres are designed for performance coupes and sedans, and even for many street-driven exotic sports vehicles. Tyres with this rating are commonly listed in the ultra-high performance all-season tyre group. They generally offer many performances for the street, including highly "spirited" (but cautious) drivers. At the same time, W speed rated tyres don't necessarily leave out the common driving factors such as comfort, ride quality, road noise, and tread life warranty.
T Speed Rating
A T speed rating shows that the tyre is approved for speeds not above 190 km/h (118 mph) under optimal conditions. It is among the lowest speed ratings and are not suitable for drivers who have a delight for high speed, that is why this speed rating is usually associated with standard touring tyres and everyday passenger cars. T speed rated tyres are commonly found in family sedans and minivans.
V Speed Rating
This speed rating indicates that the tyre is only approved for speeds up to 240 km/h (149 mph) under ideal conditions. The V speed rated tyres offer a top speed for racers. This rating technically gives room for higher maximum speeds as well as a taste of performance which is similar to W, Y and Z speed rated tyres.
Y Speed Rating
Y speed rated tyres have been tested at speeds up to, and above, 300 km/h (186 mph) under optimal conditions. It means that the tyre is rated up to 300 km/h but not limited to that speed. A Y speed rating denotes maximum tyre performance. Tyres in this bracket usually give optimum performance. Examples include the top-level ultra-high-performance Michelin Pilot Sport 4 S and Continental ExtremeContact Sport. The Pilot Sport 4 S has been tested at speeds above 300 km/h, that is why it is rated Y. The Continental at speeds up to 300 km/h is rated Y also, although, there are some sizes of the ExtremeContact Sport which are W speed rated.
R Speed Rating
R speed rating gives room for speeds up to 170 km/h (106 mph) under ideal conditions. R rated tyres generally perform a specific function or unique performance over maximum speed ability. These tyres are not standard but can be found on some heavy-duty light truck (LT) tyres and many studless winter tyres.
Q Speed Rating
Tyres with Q speed rating are only allowed an optimum speed of 160 km/h (99 mph) under normal conditions. This speed rating is toward the low end of the speed rating scale. Just like the R-rated tyres, they often prioritise a specific function, or they always have a peculiar performance over maximum speed rating.
S Speed Rating
An S speed rating shows that the tyre has been approved for speeds within 180 km/h (112 mph) under optimal conditions. Most passenger vehicle tyres are S speed-rated, but they often prioritise specific performance or function over speed.
M & N Speed Ratings
The M speed rating indicates the tyre has been approved for speeds up to 140 km/h (87 mph) and the N speed rating shows that the tyre is approved for speeds up to 130 km/h (81 mph) under optimal conditions. You'll find M and N ratings on tyres which are meant for temporary use only such as spare tyres or space savers.