How a Tire Speed Rating Can Affect Handling

The Autobahn highway in Germany is world-renowned for its high speeds.

On your tires, you find a specific marking declaring the rating of your tires. These ratings have an intricate relationship with the handling of your car and determine the speeds at which it is safe for you to travel.

Identification

Tire speed ratings indicate the top speed at which that the tire is able to perform, so there is a correlation between the handling of your car and the speed accorded that rating. Ratings range from letter markings M-Y. If you have an M rated tire, your car and tires should be able to handle well at speeds up to 81 MPH. Y rating denotes tires that can perform well at speeds up to 186 MPH. Due to a quirk in the rating system, the Z rating (149 MPH) is actually lower than the X and Y rating. Don't exchange current tires for those with lower speed ratings on your car. Both handling and steering could be compromised.

Mixing Ratings

Having differently rated tires on the same vehicle may result in poor handling. One of the reasons for this is that the tires will ultimately wear at different rates. More importantly, you may end up with only a portion of your tires truly being capable of handling higher speeds.

Fun Fact

Tire ratings stem initially from the high-speed activity on Germany's Autobahn highway. Instead of posting actual speed limits, some of the high speed lanes on the Autobahn have "speed minimums" where going too slow is breaking the law.

References

• Tire Rack: Mixing Tires
• Driver Sense: Speed Rating Explained
• Tire Rack: How to Read Speed Rating