Choosing tires with the right speed rating ensures proper handling and smooth car functioning. A chart denoting tire speed rating codes is an essential reference when buying new wheels for your automobile.
Identifying the Speed Rating Code
The speed rating is denoted by an alphabet placed to the immediate right of the load rating, towards the end of a tire’s sidewall code.
For example, in the code – P215/60R16 100H, H denotes the speed rating and 100 is its load rating.
All vehicle tires are not created equal. If you are planning to put new wheels on your car, it’s essential that you know how to read the tire code specifications that are printed on their sidewalls. Each tire comes with its unique set of specifications, that includes the maximum load rating, size, width, and height specifications, besides the speed rating.
While shopping for tires, you need to go beyond just looking for the best brands. Just like it’s important that you find the best fitting shoes for yourself, it’s essential to find the right wheels for your automobile which can handle the load and survive the driving conditions you subject your vehicle to.
To be a discerning buyer of car tires, you need to learn to decipher tire rating codes. Your car manual will have information about the correct tire specifications for your car model. In this WheelZine article, we present all that you need to know about tire speed rating, that’s printed on sidewalls of all vehicle tires.
What is a Tire Speed Rating?
The speed rating is indicated by an alphanumeric code, to denote the maximum speed that can be handled by the tire, after which it is bound to suffer major wear and tear. Generally, car tires are designed, to endure their maximum rating speed, for not more than ten minutes, after which they will breakdown.
So the maximum speed value should not be attained or exceeded, to maximize tire life. The degree of friction that a car tire can handle is dependent on the quality of material it’s manufactured from, and the degree of load its subjected to. To ensure long life, it is essential that you match the maximum speed limit of your car’s engine, and install car tires which have a rating exceeding that limit.
Note: Never downgrade the speed rating of your car tires. That is to say, never go for new tires with a lower than recommended rating, as it may result into steering difficulties and improper handling. Also, it’s not recommended that tires with different speed ratings be used together in a car, as it can lead to major handling issues.
How to Determine the Speed Rating of a Tire?
The ISO Metric sizing system
The ISO Metric sizing system provides an alphanumeric code which is used to determine the rating of a car tire. If you read the code off any car tire, it will look something like ‘P215/70R16 100V’. In this code specification, the rating is always specified last, next to the load rating. Here 100 is the load rating of the tire and speed rating is ‘V’, which indicates a maximum speed of 149 miles per hour.
Here are the most commonly used speed rating codes for cars in Europe and USA. For the complete listing of rating codes, scroll below.
Tire Speed Rating Codes
Here is the complete speed rating chart, which interprets the alphanumeric code specified on the car tire wall into the maximum speed limit specification in miles per hour (mph) and kilometers per hour (km/h).
|Speed Rating Code||Max Speed Limit (mph)||Max Speed Limit (km/hr)|
|Z||Over 149||Over 240|
|(W)||Over 168||Over 270|
|(Y)||Over 186||Over 300|
Hope reading this article wasn’t a very tiring experience. Using the rating chart presented above, you can determine the maximum speed that a tire can bear before giving in to the forces of friction. If you have a sports car, you will have to opt for tires with a high speed rating bordering in the Z, W or Y zone. However, for city-commuting cars and pickups, you can opt for tires with sub-Z rating. Refer to your car manual for the exact specifications and buy accordingly.