What Is Service Index On Special Tires For Trailers

Get down to centre level with your tires, and yous may notice the hieroglyphic-like sequence of letters and numbers imprinted into each sidewall.

The numbers and letters at the end of the sequence that you see on your sidewall correspond to what'south chosen the "tire service description" — three or 4 figures that signify both the tire load index and the tire speed rating. The load index indicates how much weight a tire can safely carry at maximum air force per unit area, and the speed rating represents the maximum operating speed.

If y'all're nonetheless confused, if you simply need to detect out your tire speed rating or if you take no thought what the tire load index or Z speed means, and then you're in the right place. We're hither to help you get a grasp on what those mysterious codes on your tires mean, how much weight your tires tin acquit and the maximum speed capability when the tire is properly inflated.

Tire Load Index

Want to observe your tire load index, also known as the load conveying capacity? Locate the 2 or 3 digits at the end of your tire size — the fancy, technical proper noun for the long string of letters and numbers encircling your tire — that precede the single letter.

Load and Speed Rating | Tire America

For example, if yous encounter "88S" at the end of the tire size, the load index would be 88. Then what does that mean for you lot? By and large speaking, the higher the tire load index, the more weight the tire can safely bear. In the case of a tire with an 88 load alphabetize, that tire would exist able to back up i,235 pounds at maximum air pressure. When you multiply that corporeality for a single tire past iv, your vehicle'south maximum load capacity would exist 4,940 pounds.

Tire Speed Rating

To discover your tire speed rating to reference the single letter at the cease of your tire size — this will be where you lot'll find the speed rating for all tires manufactured since 1991.

The most common tire speed ratings are 50, M, N, P, Q, R, South, T, U, H, Y and (Y) — letters that designate speeds ranging from 75 to above 186 miles per hr.

Speed Rating Chart | Tire America

Z-speed Tires

Unless you lot're regularly driving on — or dreaming about driving on — the Autobahn in Germany, you may accept never even heard of Z-speed tires. Audio fast, don't they? Well, that'southward because they are. When they were outset created, Z-speed tires were meant to represent the highest tire speed rating e'er — speeds that exceeded 149 miles per hour.

What you might not know is that, since Z-speed tires were created, tires with even higher tire speed ratings have been introduced: enter the Westward-speed, Y-speed, and (Y) speed tires. Tires with speed ratings of W, Y, and (Y) can withstand the highest speeds, such equally those you'd find when driving an exotic sports auto, of 168 to 186 miles per hr and to a higher place.

If you've ever wondered how former your tires, information technology's an piece of cake bit of information to detect out tires really have a "born-on" date, and it's listed correct on the tire itself.

How to Observe Your Tire Load Index and Tire Speed Rating

If yous're unable to clearly read the tire size from the sidewall of your tire, you tin also locate your tire load index and tire speed rating in your owner's manual, within your glove compartment and gas tank hatch and on your driver's side doorjamb. Of course a tire professional will always be willing to help.