Understand the Tire Speed Rating

Purchasing a new set of tires for your vehicle is not a simple process. There are multiple things to know about them, and based on several parameters, you can decide which tires to get. A crucial parameter that you should keep in mind is the tire speed rating.

What is tire speed rating?

A tire speed rating is the maximum speed at which you can drive your tires safely. Once you pass the threshold, the performance drops, and they are no longer considered safe. In some instances, the tires may start to degrade, which can be catastrophic.

Why were tire speed ratings developed?

As cars became faster throughout history, tire manufacturers had to keep up the pace and design tires to withstand the speeds. Over time, more manufacturers started to get in on the business, and more models were introduced. To keep the price range wide and offer cheaper and more expletive premium tires, certain decisions had to be made.

One of those decisions is the tire speed rating. The general rule is that the lower the price, the lower the speed rating. This was also good news for less powerful cars as they didn’t have any need for high-performing tires that can be operated at a speed much higher than the vehicle can reach.

Where can I find my tire speed rating?

The tire speed rating will mostly depend on your vehicle, so the first place to look is the user manual. Alternatively, you can look at the maintenance stickers at the door or in the glovebox.

If your previous tires were purchased per the manufacturer’s requirements, you could use them as a guide. You can find the tire speed rating on the sidewall right next to the size and load index. For example, if the sidewall says: “195/70R13 75M,” the tire speed rating is the last letter “M.”

ZR Designation

Before explaining the ZR designation, first, let’s look at the other ratings. The speed rating ranges from 75 mph and goes over 186 mph. Each increase is several miles per hour higher than the previous one and gets a letter that helps you identify the rating quickly.

The ZR designation is aimed at higher performance cars that can reach maximum speeds over 149 mph. This is a separate category consisting of 3 speed ratings: 168, 186, and above 186 mph.

Tire speed rating chart

There are 15 speed ratings for cars, and you’ll be able to find each in the chart below. Keep in mind that the letters are not in order, and if you notice some of them out of place, it’s not a typo; that is how the ratings are marked.

FAQs

Does speed rating really matter?

Yes. Each tire is designed to be driven at a certain maximum speed. Getting tires with higher speed ratings will not provide any advantages. On the other hand, I wouldn’t advise you to get tires with a lower speed rating than the manufacturer’s requirements.

Does the speed rating affect ride quality?

No, the ride quality on the tires is not affected by the speed rating.