The speed rating, “H” in the diagram, denotes the speed at which a tire is designed to be driven for extended periods of time. You should know that the placement of the rating information has changed over the years. Prior to 1991 they would have appeared on the tire this way:
P212/65HR15 or P212/HR16 95H.
Since 1991 you will see this designation: P212/65R15 95H.
It is important to know that the ratings assume that the tire is not damaged and is not carrying loads that exceed the tires load rating. Even if a tire has been repaired the manufacturer will not guarantee the rating will hold up as they cannot vouch for the quality of such repair(s).
The ratings range from 99 miles per hour (mph) to 186 mph. These ratings are listed below. If the increments seem a bit odd it is because they were first established in kilometers per hour and were later converted to miles per hour. Obviously all tires are rated to handle all United States speed limits and are more than capable of going well beyond them. All manufacturer’s, however recommend against using their tires in excess of any legal speed limits. Below is a table which shows speed ratings and the typical use for each.