Tyres like other parts of a vehicle has its own 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.
Just like you like load rating, when you shop for a new tyre for your vehicle you need to always ask for the speed rating. If you are shopping for your tyre online some online stores will show you the speed rating before you pay when some will not show you unless you requested for it. It is always necessary to use a tyre with a speed rating that is recommended by your car manufacturer although it is still ok to use a tyre with a speed rating that is a bit greater. for example, instead of making use of an H-rated tyre on the Audi A3, you could make use of a V-rated tyre with a speed rating of 149 mph. In case, it is compulsory for you to mix tyres with different speed ratings, ensure to take note of the lowest speed rating when driving.
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 130 miles per hour which indicates that under optimal conditions, the maximum speed the tyre can attain is 130 miles per hour. Please note, this does not give you the audacity to reach 130 mph whenever you are driving your car, always observe the proper speed limit as declared by your State’s law.
In this post, I will open your eyes to the various speed ratings that exist and I will take my time to give concise explanations on them.
H Speed Rating
This is the first speed rating on my list. An H speed rating indicates the tyre is approved for speeds not more than 130 mph (210 km/h) under optimal conditions. An H speed rating is at the low level of the performance tyre speed ratings. The H speed rated tyres are good for sport and luxury coupes, but not typically listed as top-rated performance vehicles’ speed ratings and are commonly listed in the grand touring all season tyre category.
W Speed Rating
The W speed rating indicate that the tyre is approved for speeds up to 168 mph (270 km/h) under ideal conditions. Tyres that are W speed rated firmly land at the performance end of the tyre speed rating spectrum. W speed rated tyres are good for performance coupes and sedans, and even for many street driven exotic sports vehicles. The W speed rated tyres are commonly listed in the ultra-high performance all season tyre group. W speed rated tyres 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 everyday 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 118 mph (190 km/h) under optimal conditions. This is among the lowest speed ratings; the T speed ratings is not suitable for drivers who have great 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 family sedans and minivans.
V Speed Rating
This speed rating indicates that the tyre is only approved for speed up to 149 mph (240 km/h) under ideal conditions. The V speed rated tyres offers a top speed for racers and drivers that enjoy driving at high speed. The V speed rating technically give room for a higher maximum speed 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, 186 mph (300 km/h) under optimal conditions. This means that the tyre is rated up to 186 mph but not limited to 186mph. A Y speed rating denotes maximum tyre performance. Y speed rated tyres 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 186 mph that is why it is rated (Y). The Continental at speeds up to 186 mph is rated Y also although, there are some sizes of the ExtremeContact Sport which W speed are rated.
R Speed Rating
R speed rating give room for speeds up to 106 mph (170 km/h) under ideal conditions. R rated tyres generally perform a specific function or unique performance over maximum speed ability. R speed tyres are not common but can be found on some heavy duty light truck (LT) tyres, many studless winter tyres.
Q Speed Rating
Tyres with Q speed rating are only allowed an optimum speed of 99 mph (160 km/h) under normal conditions. This speed rating is toward the low end of the speed rating scale. Just like the R rated tyres they often prioritize a specific function or they always have a peculiar performance over maximum speed rating. Many studdable and studless winter tyres have this speed rating.
S Speed Rating
An S speed rating shows that the tyre has been approved for speeds within 112 mph (180 km/h) under optimal conditions. Most passenger vehicle tyres are S speed rated, but they often prioritize specific performance or function over speed.
M and N Speed Ratings
The M speed rating indicates the tyre has been approved for speeds up to 87 mph (140 km/h) and the N speed rating shows that the tyre is approved for speeds up to 81 mph (130 km/h) under optimal conditions. You’ll find M and N ratings on tyres which are meant for temporary use only such as spare tyres.