Q. How often should my tyres be checked?
A. Tyres should be inspected at least once a month and before any long journey. Checks should include checking the air pressure, overall condition and tread depth. And don’t forget to check the spare or the compressor and sealant if no spare was fitted!
Q. What should I do when checking my tyres?
A. Tread depths should be checked to ensure they meet the legal minimum regulations. Pressures should be checked in line with the vehicle manufacturers’ recommended settings. Take care to increase the pressure if the vehicle is heavily loaded as shown in the car makers recommendations. The tyres should also be given a thorough visual inspection to look for any cuts, lumps or bulges. Also look for any objects embedded in the tread which should be removed.
Q. What is the minimum legal tread depth?
A. Current New Zealand law requires car, 4WD and vans to have at least 1.5mm of tread across the central three-quarters of the tyre, around its entire circumference.
Q. Why is tread depth important?
A. Adequate tread depth is essential for good grip on wet roads as the tread pattern helps to remove water from between the tyre and the road surface. Drivers with insufficient tread depth face longer stopping distances, reduced grip and an increased risk of aquaplaning.
Q. Why is correct tyre pressure important?
A. To stay safe on the road your car needs to have the correct tyre pressure. If the tyres are under or over inflated then handling and grip will worsen, potentially causing irregular or unpredictable car behaviour. Tyres with insufficient air are also more likely to suffer from a blowout and will suffer premature wear on the outside edges of the tyre.The wheel rim and tyre will be more susceptible to impact damage. Low tyre pressures dramatically reduce tyre life.
Over-inflation results in less comfortable ride, a reduced area of contact with the road giving less grip in the day and accelerated wear on the tread centre .
The benefits of a properly inflated tyre, include reduced running costs and longer tyre life.
Q. Where can I find the correct pressure for my tyres?
A. The vehicle manufacturers’ handbook contains this information, as well as it being available inside the fuel filler cap or driver’s door sill. Many tyre retailers will also be able to provide this information.
Q. What causes irregular wear?
A. Irregular wear can be caused by a number of factors. Repeated scuffing of tyres against kerbs, misaligned steering, aggressive driving, the over- or under-inflation of the tyre, worn suspension parts, are just some reasons. There are so many variables that there is no one single answer.
Tyres should be checked regularly for any signs of wear and replaced accordingly.
Q. How many miles can I get from my set of tyres?
A. Tyre life is very dependent on the way that they are used. A set of tyres well maintained and used exclusively on motorways can return a much higher mileage against tyres badly maintained and ill-treated in a city centre and urban environment.
Q. How far/fast can I drive with a special ‘run flat’ tyre in a deflated condition?
A. Recommendations in the area may differ from tyre manufacturer to manufacturer and drivers should always consult the car manufacturer’s handbook for the distance that can be travelled and speed driven. Please note that standard tyres should not be run without air or this will cause irreparable damage.
Q. What are winter tyres?
A. Winter tyres have been designed to specifically cope with snow and ice, as well as cold and damp conditions. Below 7 degrees celsius the tread compound in normal tyres begins to harden, providing less grip. Winter tyres use advanced silica compounds so they remain pliant in cold temperatures, giving more grip and shorter stopping distances. They also have specially designed tread patterns to give superior grip on ice and snow.
Winter/snow tyres perform very poorly in New Zealand driving conditions with poor roadholding in wet road conditions. Also, they tend to be noisey and wear out quickly,
Q. Is it safe to use a tyre sealant or Tyre Pando?
A. Bettertyres does not recommend pre-puncture sealants as there is an inherent risk of the primary damage extending in service and/or of internal secondary damage. The continued use of this tyre in such a condition may lead to serious tyre failure. Post-puncture sealants are regarded purely as a “get you home” measure and introduced following a puncture. The manufacturers recommendations detailed on the can should be strictly followed.
Q. What do the sidewall markings mean?
A. The sidewall markings provide descriptive information about the tyre. The most important markings for drivers in the New Zealand are size and type, aspect ratios load and speed indices (service description).
Q.Should I fit four new tyres at a time?
A. It’s better to fit all four tyres at the same time but if that is not possible then fitting two tyres at a time, and as a pair to get the best handling and grip on each axle, is the next best option. As a last resort, then a single tyre can be replaced.
Replacing all 4 tyres at the same time guarantees that all 4 tyres are the same; if you only buy two, there is no guarantee the tyre of your choice will be availble next time you buy tyres.
Q. Which is the best axle to place new tyres on?
A. New tyres on the rear axle provide better driver control on wet roads. This is because tyres with deeper tread are better at displacing water and give better grip. If the new tyres are fitted at the front the car, then it is more likely to oversteer when grip is lost in wet weather, which is much harder to control than understeer. Oversteer is when the rear of the car slides sideways, and understeer is when the front of the car slides.