Tyre Guide

This guide will help you understand the basics of tyres and their maintenance.

• Age & Warranty
• Inflation Pressure
• Nitrogen Inflation
• OEM marks
• Read Tyre Sizes
• Speed & Load ratings
• Wheel Rotation

Age and Warranty

Age - Tyre manufacturers mark the sidewall of their tyres with the date of manufacture. In the below image the tyre is marked 0907 indicating production in week 09 of year 2007. Tyres do not have an expiry date

Warranty - All manufacturers must warrant their tyres for 6 months from date of purchase, in line with the CPA. Some brands offer you a lot more.

In the event of tyre failure, stop the vehicle as soon as is safely possible. If you suspect a manufacturing defect, submit your damaged tyre to your local tyre fitment center who will advise you of the best course of action.

Inflation pressure

Tyre pressure maintenance is the single most important aspect of tyre management and has a direct impact on steering, handling, braking, ride comfort, fuel economy and tyre wear.

The tyre's internal air pressure enables it to support the load exerted by the vehicle. It also assists in expanding the tyre to the designed shape. As you increase the vehicle load the tyre begins to deform from the design shape, requiring that you increase the pressure to compensate for the increased load.

You will find the recommended pressures for your vehicles tyres in your user manual and also on a sticker in the drivers door or inside the fuel filler flap. Note that your front and rear tyres may require different pressures.

Check your tyre pressure every two weeks or when you have a significant change of load, as indicated by your user manual. It is best to check your pressure when the tyres are cold, in the shade. Keep an accurate pressure guage in your car, this will enable you to check your tyres before the onset of your journey.

Nitrogen Inflation

Nitrogen enables your tyres to run cooler and also reduces the rate of pressure loss.

• normal air contains 78% nitrogen, 21% Oxygen and 1% other gases.
• as your tyre loses pressure it is mostly the smaller oxygen molecule escaping. Each time you reinflate with air you have a gain in nitrogen content which, over time, offsets the benefit of paying to fill with nitrogen.
• nitrogen filled tyres deflate just as quickly in the event of a puncture or damage.

OEM marks

Vehicle manufacturers conduct intensive research into the tyres that they fit to their vehicles. Once a tyre is approved for a vehicle, the manufacturer is permitted to mark the tyre accordingly. This mark is helpful in selecting replacement tyres for your vehicle, knowing that they have already been tested and approved by the vehicles manufacturer.

A list of the more common tyre marks and their respective vehicle manufacturers is tabled below. These markings are normally found at the end of a tyre description and are also marked on the sidewall of each applicable tyre.

Read Tyre Sizes

Reading the size of your tyre is important to ensure that you have the correct tyres fitted to your vehicle. In addition to your safety and mechanical integrity of your vehicle, other considerations are your vehicle manufacturer and insurance company may take a negative view of your fitting tyres that are not within their specifications, potentially resulting in your warranty or claim being rejected.

In this image the size of the tyre is 195/55R16 87V.

Speed and load ratings are all based on the correct pressure being maintained.

Tyre Speed rating - The maximum speed (based on a test of 10 minutes duration) at which a tyre can be safely operated, when loaded according to it's Load Index and when inflated to it's recommended pressure.

The speed rating Z is still included in some tyres size markings. Z rating indicates capacity for speeds in excess of 240km/h or 300km/h, depending on the specific tyre. Z rated tyres may also be marked with W or Y after the load index. If you are uncertain if the tyre you are selecting fits with your vehicles capabilities, please contact the tyre manufacturer.

Tyre load index table - The maximum mass each tyre can carry, based on the respective Load Index, at the speed indicated in it's Speed Index, when inflated to it's recommended pressure, up to 210km/h (240km/h on ZR).

Wheel rotation

Why rotate your wheels? Due to a variety of factors, tyres do not wear evenly throughout your vehicle. Some wheel positions wear faster than others. Rotating wheels results in a more even wear rate on your overall vehicles tyres.

More useable tread means better grip. Having one or two tyres worn more than the others may result in a loss of traction. Punctures are also more prone to occur to tyres with less tread. Rotating your wheels ensures that all tyres wear at a more even rate resulting in more Km per tyre.

5 wheel rotation results in spreading the wear over more tyres which reduces the rate of wear per tyre, resulting in less frequent replacement of tyres. 5 wheel rotation ensures that the spare wheel is brought into the equation, it’s value utilised and that whichever tyre is spare is of a known condition.

Tyre and vehicle manufacturers recommend that you rotate your wheels every 8 000 - 10 000km. You will need to check the recommendations of both your vehicle manufacturer and tyre manufacturer to determine what best suits your vehicle.

Most vehicles can have their wheels rotated although some manufacturers have included sensing equipment into their vehicles which, when the tyres are mismatched, will restrict the use of the vehicle. This may result in your having to replace all 4 tyres. Check with your vehicle manufacturer to see if your wheels can be rotated.

Wheel Alignment maintenance is an important factor in ensuring your safety and extending tyre life and should be conducted at the same time as the tyre rotation process.