Reading your tire can be confusing, and trying to understand it can be exhausting. But remember, the information is there for a reason! It’s important and can be extremely useful to you later on. The information on your tire sidewall can help you figure out what type of tire you should buy as a replacement, identify the quality of your tire, learn what speeds are safe to drive, or discover the amount of weight they can hold. To do all of these things and more, follow this breakdown explaining how to not only read, but also understand your tire.   

• The first letter tells you the tire’s class: P = passenger, LT = light truck, etc.  
• The section width is the width of the tire from one sidewall to the other in millimeters.
  • Ex: 225 mm
• The height of the sidewall is the aspect ratio, which is a percentage of the section width; in other words, the ratio of sidewall height to width.
  • Ex: 25% (of 225 which means the section width is 56.25 mm) 
• The speed rating is the maximum speed at which a (properly installed and inflated) tire can be driven on; this is indicated by a letter which stands for a specific mph.
  • Ex: S = 112mph, T = 118mph, W = 168mph
• An R stands for radial construction, which indicates the tire is a radial tire; these tires have layers of fabric whose cords run at right angles to the circumference of the tire, meaning the tread is strengthened by additional layers around the circumference.
• Wheel diameter is the size of the wheel that a tire can fit, in inches.
  • Ex: The tire will fit a 18-inch wheel.   
• The maximum load carrying capacity of the tire is the load index; it’s very important that you don’t exceed this specification.   
• DOT is the department of transportation number; this indicates that the tire has passed all of the minimum DOT standards for it to be sold in the U.S.  
• UTQG stands for uniform tire quality grading marking, which is a rating for treadwear, traction, and temperature resistance:
  • Treadwear rating (440) refers to the durability of the tire.
  • Traction rating (A) refers to the tire’s ability to stop in a straight line or wet road (grades are AA, A, B, or C – AA being the highest).
  • Temperature rating (A) refers to the tire’s resistance to the generation of heat when driven at high speeds (grades are A, B, C – A being the highest).