The speed rating tells you the speed the tyre can safely maintain over time
A higher speed rating usually means you will have better control and handling at higher speeds — and that the tyre can take the extra heat. As a general rule, tyres with higher speed ratings also handle better at slower speeds.
The U.S. Department of Transportation (DOT) set the ratings scale, shown above. But tyre makers test their own tyres and assign their own speed ratings. On the sidewall of every tyre, you’ll find one of these speed rating code.
Safety and Speed Ratings
When you get new tyres, choose tyres with at least the speed rating your car or truck’s manufacturer recommends. It’s ok to move up to a higher speed-rated tyre, but don’t go lower.
The speeds shown are test speeds; they are not recommended speeds. To be safe, please obey road speed limits.