How to read a tire width and the aspect ratio?
Example: 205 / 55
These are important tire markings that will help you find the right tire when you need to change it.
The first of the two numbers is the nominal section width of the tire. It is given in millimetres and defines the distance between the inner and outer sidewall of the tire. For example, 205 means that your tire is nominally 205 mm wide.
The second number is the relationship between a tire’s sidewall height and the tire's width. It is expressed as a percentage. For example, 55 indicates that the sidewall height, between the top of the tread and the rim, is 55% of the tire width.
How to read a tire construction type and the wheel diameter?
Example: R 17
These tire markings are usually composed of a letter and a number.
The letter, R, indicates that the tire’s internal construction is Radial.
Radial technology, invented by Michelin, uses combinations of rubbers and metal and textile reinforcing materials to form very robust structures in the tread area but flexible sidewalls. It allows a longer tread life and reduces fuel consumption thanks to the reduction of the rolling resistance.
After the letter, you will find a number. In our example: 17.
This number is expressed in inches and indicates the diameter of the wheel on which the tire is designed to fit.
