Tyre size is a standardized system for indicating the dimensions and characteristics of a tyre. Numbers typically indicate it, and letters are printed on the tyre’s sidewall. The tyre size tells you the tyre’s width, aspect ratio, construction, and diameter, as well as other information, such as the tyre’s load-carrying capacity and speed rating.
Numbers typically indicate tyre size and letters printed on the tyre’s sidewall. Here is an example of how to read a tyre size:
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- “195” is the width of the tyre in millimetres. This measurement refers to the distance from one sidewall of the tyre to the other when it is mounted on the wheel and inflated to its maximum pressure.
- “65” is the aspect ratio, the height of the tyre sidewall as a percentage of the width. In this example, the sidewall is 65% of the tyre’s width.
- “R” indicates that the tyre has radial construction, which means the tyre’s ply cords run radially across the tyre from bead to bead.
- “15” is the diameter of the tyre in inches. This measurement refers to the distance from one end of the tyre to the other, passing through the centre of the wheel.
- “H” is the service description, which indicates the tyre’s speed rating. The speed rating is a letter that corresponds to the maximum speed at which the tyre can be used safely. The letter “H” corresponds to a maximum speed of 130 mph.
It’s important to use tyres that are the correct size and load rating for your vehicle to ensure safe and reliable driving. You should consult the owner’s manual for your vehicle or contact the manufacturer to determine your car’s appropriate tyre size and load rating.
