Tire Markings Explained: What does the code on the tire mean?

Tire markings might confuse many people, as they cannot find their way around various numbers and letters on the tire. The markings convey important information about tires, such as size, specs, and what kind of safety standards were met.

This extensive guide will show you how to decode the markings on a specific example, so you won't get lost when you see the symbols on the rubber of a tire.

Content

• What do the numbers on tires mean?
• Secondary tire markings explained
• Load index
• Speed index/rating
• Other tire markings
• Manufacturing date code (DOT)
• Common tire labels explained
• E mark table
• Conclusion

What do the numbers on tires mean?

The main marking on the tire consists of a string of numbers (see the orange part of the string on the image) and might look like this: 205/65 R15. These numbers indicate the tire size, thus, are essential to ensure the tires fit your car. You can check your car's handbook for the appropriate size of tires. Let's split this string and decode each part:

• 205 - Tire width in millimeters (from one sidewall to another)

• 65 - Aspect ratio (tire height as a percentage of tire width, i.e., the height of this tire is 65% of the tire's width)

• R - Construction of the tire - in this case, 'R' is abbreviated from "Radial" (you might also come across 'B' for Bias belt and 'D' for Diagonal)

• 15 - Wheel/rim diameter in inches

Secondary tire markings explained

Besides the main marking, various other symbols on the tire might be confusing at the first glance. First, let's have a look at the secondary symbol from our example (see the image, white text on the tire) above that appeared after the main marking. The symbol is 91V, and can be divided into a number and a letter.

• 91 - Load index, in this case, the maximum load is 615kg

• V - Speed index/rating, in this case, the maximum speed is 240 kph (150 mph)

Load index

The load index represents a number and refers to a tire's maximum load in kilograms. The table below displays common load indexes and their respective loads. The load index for passenger tires usually spans from 75 to 105, though you can see indexes not included in this table if checking the tires for other types of vehicles.

Speed index/rating

The speed rating is represented by a letter corresponding to the maximum speed a tire can sustain when carrying its recommended load.

You might find it odd that the letter 'H' appears after 'U,' but it is not a mistake. If you check the complete table of speed indexes starting from the letter 'A,' you'd see that the letter 'H' is not present in the lower end.

Other tire markings

There are various other symbols besides the main and secondary tire markings. The tire usually displays the manufacturer's name, pattern, manufacturing date code, maximum load, temperature grade, and other symbols. It can also have tread wear indicators (TWI), country of manufacture, and E mark if the tire passes the EU's (European Union) safety standards.

Manufacturing date code (DOT)

The tire's manufacture date is marked, for example, as DOT F3OF OBDX 1422. The last four digits can be divided into two:

• 14 - First two digits indicate the week of tire manufacture in the given year

• 22 - Last two digits indicate the year the tire was manufactured

Common tire labels explained

E mark table

Economic Commission for Europe (ECE) introduced the so-called E mark, which is mandatory on all tires sold in European.

Besides the country that produced and approved the tire, a standardized label indicates various properties of the tires, such as:

• Grip in wet conditions

• Rolling resistance

• Road noise

These properties are graded from letters A-G, in which A is the best and G is the worst.

Conclusion

We hope this guide helped you understand various symbols and markings on the tire. If you think we miss something or want to share your thoughts, please let us know in the comments!