Read Your Tyre Size
Nominal Section Width
The first three digit numeric portion identifies the tyre’s “Section Width” (cross section) in millimeters. Here the 195 indicates that this tyre is 195 mm across from the widest point of its outer sidewall to the widest point of its inner sidewall when mounted and measured on a specific width wheel.
The two digit number followed by the Nominal Section Width is a two digit number that identifies the tyre’s profile or aspect ratio. The number 55 in the above diagram indicates that the tyre’s sidewall height is 55% of its section width. The higher this number, taller the sidewall of the tyre, lower this number, lower the sidewall.
A letter (R in this case) that identifies the tyre’s internal construction follows the aspect ratio. The tyre size above identifies that the tyre has a Radial construction in which the tyre body plies out from the imaginary center of the wheel.
The number 16 followed by the construction in the above diagram indicates the tyre and wheel diameter in inches. For information about the Load and Speed Index refer to the next section.
Speed symbol on your Tyre
It is very important that you check your speed symbols before buying your tyres. Even, when you are replacing your vehicle’s tyres it is important to ensure the new tyres, even, if they are of a different size, have the same or a higher speed symbol. Speed symbol determines the maximum speed at which it can carry its rated load. For the illustrated tyre in the above section, the symbol V limits its maximum speed to 240 kmph. Likewise, there are other speed symbols, whose related speeds can be viewed in the table below.
Load Index on your Tyre
The number following the rim diameter indicates the maximum load that the tyre can carry. Usually a rough load estimate of a tyre is determined by dividing the total load capacity of the vehicle by four and checking the result (Total Load Carrying Capacity) for the associated load index in the table below. Some vehicles require tyres that are rated to carry a higher load and therefore have a higher inflation pressure. This information is contained in the manufacturer’s handbook and the tyres will carry the marking RF (Reinforced) or XL (Extra Load).
Safety & Maintenance
Considering how important tyres are for a smooth and safe drive, it is surprising just how quick and it is easy to care for your tyres. By following these tyre care tips, and conducting simple regular checks, you will not just save time and money, but more importantly, stay safe on the road
- Do A Daily Visual Check
- Check that all tyres have about the same inflation pressure.
- Check the sidewalls for cracks or unusual bulges.
- Check for and remove any foreign objects (e.g. stones or nails) that could puncture yourtyre.
- Do A Monthly Tyre Pressure Check
- Use a proper tyreguage to measure tyre pressure.
- Your vehicle tyre pressure chart can usually be found on the driver’s door frame or in your owner’s handbook.
- Don’t forget to also inflate your spare tyre.