What Are Speed Ratings for Tires?

Service Tech with Tires

If you’ve ever stepped into a tire center, you probably noticed the wide variety of tire sizes and types lining the walls. A tire speed rating tells you the highest speed a tire can safely maintain without risk of a blowout. In order to ensure your safety while traveling around Mobile, Prichard, and Saraland, it’s important to know the tire speed rating suited for your vehicle.

At Nissan of Mobile Tire Center, our knowledgeable team of professionals are a great resource the next time you’re in need of tire replacement. Continue reading our helpful guide to learn how to find the right tire speed rating for your vehicle.

How to Identify a Tire’s Speed Rating

Before a tire can be legally sold in the US, it must first pass a strict inspection process overseen by the Department of Transportation. This is to ensure that the tires placed on your vehicle can properly withstand typical road conditions while maintaining their integrity.

A speed rating is assigned to each tire signifying the maximum speed the tire can safely travel. A speed rating often will exceed the recommended travel speed and always will be higher than the legal speed limit.

Each tire then receives an alphabetical code placed on the tire’s sidewall. The most common speed rating codes include:

  • T – this is the most common speed rating and can reach up to 118 MPH.
  • H – most commonly found on high performance vehicles and can reach up to 130 MPH.
  • V – can reach up to 149 MPH.
  • W – can reach up to 168 MPH.
  • Z – a “Z” rating is designated for any tire that can safely exceed 148 MPH and in some cases might be used in place of “V” or “W”.

You should never use a tire that doesn’t match your vehicle’s specifications as it can result in a dangerous blowout. Your vehicle’s owner’s manual is a great resource to consult or you can often find your vehicle’s tire info located inside your driver’s door well.
Reading a Tire’s Sidewall

Tire Size in Sidewall

When it’s time to replace your tires, the first thing you’ll be asked by a service professional is to provide the 9-digit alpha-numeric code located on your tire’s sidewall. This code includes your tire’s speed rating along with other important tire size information like:

  • Type. This is at the start of the code and normally begins with the letter “P” for passenger vehicle or “LT” for light truck.
  • Tire Width. Directly following the tire type, this three-digit number denotes the millimeter width of the tire.
  • Aspect Ratio. Preceded by a slash mark, this two-digit number denotes the size of the sidewall.
  • Diameter. The next two digits in the code tell you what size rim the tire fits.
  • Speed Rating. The last set of numbers denote the max weight and speed the tire can safely maintain.

Schedule Service at Nissan of Mobile

If you’re a driver living near Mobile, Prichard, or Saraland in need of a partial or full tire replacement, simply stop by our tire center during business hours or go online to schedule an appointment today!