The numbers and letters on the side of your tyre have very specific meanings.
A tyre’s sidewall is pretty much what it sounds like – the outer and inner “walls” on the sides of a tyre. Every sidewall has its own unique information that is divided into four main sections:
1. TYRE SPECS
This describes the fundamental characteristic of your tyre. Size, construction, speed rating and more.
TYRE TYPE: This designates the type of vehicle the tyre fits. P is for passenger metric. Other letters are LT (light truck), T (temporary spare) and ST (special trailers). If your tyre has no letter, this signifies a Euro “metric” size.
2. DEPARTMENT OF TRANSPORTATION SAFETY CODE
This assures that your tyre complies with all Department of Transportation (DOT) safety standards. After the DOT insignia is your tyres indetification number, which begins with the tyres manufacturer and plant code where the tyre was manufactured (two numbers or letters). The ninth and tenth characters tell you the week the tyre was manufactured. The final number(s) signifies the year the tyre was manufactured.
DOT: Department of Transportation Safety Code
3. UTQG CODE
The Uniform Tyre Quality Grading (UTQG) was established by the National Highway Traffic Safety Administration (NHTSA) to test tyres following government-prescribed test methods and then grade each tyre on three main components:
- Treadwear: This is the wear rate of the tyre, comparable only to other tyres within a tyre manufacturer’s line. The baseline grade is 100. Therefore a tyre with 200 would theoretically last twice as long on the government’s course compared to a tyre with 100.
- Traction: Traction grades are AA, A, B and C (with AA being the highest grade). They represent the tyre’s ability to stop straight on wet pavement as measured on a specified government track. Any tyre rated under C is considered unacceptable for road travel.
- Temperature: The temperature grades, from highest to lowest, are A, B and C. These represent the tyre’s ability to dissipate heat under controlled indoor test conditions. Any tyre rated below C is considered unacceptable.
Some tyres have unique benefits, as showcased with specific icons. For example, a Mountain Snowflake symbol tells you that the tyre meets or exceeds industry-established snow traction performance requirements.