Tire Basics: How to Read a Tire Sidewall

September 08, 2017

Do you wonder what the markings on the side of the tire stands for? Printed on the side of your tire are important letters, numbers, and icons. Learning to read them will give you vital information about your tires. There are many letters and numbers – more than 25 – so we will divide them into different clusters for easier reading: Bridgestone Logo, Manufacturing Code, and Tire Specifications.

1. Manufacturer’s logo

Every tire has a brand logo that identifies its manufacturer. The Bridgestone logo represents high quality, safety, and value.




2. Manufacturing Code

Following the letter and numbers are indicators for the tire’s manufacturer and the date of manufacture. The last four numbers you see tell you the date of its production. The first two numbers indicate the week of manufacture, while the last two numbers are for the year. In sum, this information basically tells you who created it, and when it was created.

3. Tire Specifications

This is not as complicated as it seems. These letters basically give you information about your tire’s construction, function, and capabilities. Tire Specifications include tire type, tire width, aspect ratio, construction, wheel diameter, load index, and speed symbol.

Tire Width: This number shows the thickness between your inner and outer sidewall in millimeters.

Aspect Ratio: This number shows the proportion of the tire’s sidewall height to the tire’s width; the number may reflect the maneuverability of the tire.

Construction: This letter shows how the tire was constructed inside. “R” stands for radial construction. Radial tires are used for Sedan and SUVs. Radial Tires are known to have flexible sidewall and longer tread life.

Wheel Diameter: Tires are constructed to fit around a wheel. This number in inches show the wheel’s diameter that the tire is suited for

Load Index: This number provides an assigned weight value safe for the tire to carry. The higher your tire’s load index is, the greater its load carrying capacity. Load index vary in each tire. Check your tire and see its load capacity below.


Speed Symbol: This letter shows you the maximum safe speed a tire can achieve. The chart below will show you the most common tire speed symbols and its corresponding speeds.