To read and/or download the new VACC booklet “Important information about your tyres!” click here.
The condition of a vehicle's tyres is crucial to its safe use. Tyres are a vehicle's only contact with the road.
You've probably heard many times about the importance of checking tyre pressures and replacing worn tyres. Unfortunately, too many motorists are complacent - or careless - about the condition of the four pieces of rubber that keep a car safely on the road.
For race drivers, worn tyres or the wrong choice of tyre means the difference between winning and losing, and staying on the track or running out of control and off it.
Motor racing is a good way to illustrate the importance of tyres.
During a race, you'll notice that race cars go through many tyre changes to maintain optimum performance and low lap times.
You will have noticed that race teams change the tyres on the cars according to the prevailing weather conditions.
In dry weather, 'slicks' are used. Slick tyres have no tread, giving the tyres maximum surface area in contact with the road to grip most effectively on a dry road surface. However, slicks are useless on a wet track because without grooves to clear the water away from beneath the tyre, the tyre loses contact with the surface of the road and loses grip. A 'slick' on a wet surface will quickly and unexpectedly slide without any means of controlling it. Race drivers refer to this as 'aquaplaning'. It is a real danger for even the most skilled of drivers.
When the track is wet, racing 'slicks' are replaced by race teams with wet weather tyres that have plenty of tread - the tread disperses water from underneath the tyres to prevent aquaplaning and to maintain tyre contact with the road.
Of course, having different sets of tyres for various road conditions is impractical for normal road use. That's why conventional tyres for road use are designed with tread patterns that maintain optimum grip in both wet and dry conditions.
Road tyres must have a minimum tread depth of 1.6mm to be roadworthy. Driving on anything less is extremely dangerous in wet weather; low tread depth cannot disperse the water quickly enough allowing water build-up between the tyre and the road surface. When this occurs the car loses grip with the surface of the road and may easily and unexpectedly slide. Loss of grip from poor performing tyres is most dangerous in an emergency situation when a car needs to stop quickly, or change direction quickly.
Then, worn tyres can kill.
Tyres are a relatively low cost safety feature. Given that the life expectancy of a well-maintained tyre is up to 60,000km, the running cost can be a little as one cent per kilometre.
So there goes your excuse for not being able to afford new tyres. Realistically, if you can't afford to replace worn tyres on your vehicle, you really can't afford to be driving at all.
A VACC Accredited Tyre Dealer can offer you expert advice on the condition of your vehicle's tyres, and if they need replacing, can suggest the best tyres to fit your car and your budget.
When fitting new tyres to your vehicle, ask to have the wheels checked for balance and alignment. It's false economy if you don't. When wheels are out of alignment or balance, the tyres will wear unevenly and have a shorter life.
Check tyre pressures regularly. Under-inflated tyres will also lead to uneven tread wear, not to mention playing havoc with fuel economy.
Checking tyre pressures is also a good opportunity to keep an eye on the tyre tread. When the tread wears down, you'll notice that small bars will start to appear across the tread, evenly spaced around the circumference of the tyre. These are called tread wear indicators, and when they become clearly visible, it's time to replace your tyres.
For all your tyre needs, see your nearest VACC Accredited Tyre Dealer.
Issued by VACC, the Victorian Automobile Chamber of Commerce.
Tyre inflation
All tyre pressures (including the spare) should be checked weekly, when the tyres are cold. Refer to the tyre placard attached to your vehicle for recommended pressures. This is usually located in the glove box or the drivers' door edge.
Keeping the pressures at their recommended level will provide you with the best handling, ride and keep tyre wear to a minimum.
Always ensure that you replace the tyre valve cap once you have checked your pressures.
Tyres should also be checked regularly for cuts or any sharp objects imbedded in the tread.
The minimum legal tread depth is 1.5mm. However as tyre performance reduces once the tread depth is less than 3mm, it is safer to replace them earlier than at the legal minimum.
To equalise tread wear it is recommended that the tyres by rotated and their balance checked at every service. Please see you local Victoria Tyre Dealer Association member for help with any tyre questions you may have.
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Q.2 How often should I check the pressure in my vehicle’s tyres?
A. Generally, it is good practice to check tyre pressures weekly.
But do not stop there! Always inspect your tyres for stones wedged in the tread grooves and look for cuts or abrasions across the tread, on both the sidewalls and at the same time check for imbedded nails and screws. Do not remove these, except in a repair shop.
When checking tyres, don’t forget the spare! This should be the best tyre in the vehicle because once you have a flat, you only have 1 spare
Q.3 How do I check the pressure in my tyres?
A. Always check tyre pressures when tyres are cold – if necessary, buy a quality brand tyre gauge and keep it in your glove box ready for use.
Q.4 What pressure should I use in my tyres?
A. Always keep tyre pressures at least up to the levels recommended by the vehicle manufacturer. This information will be found on the tyre placard and in your vehicle owner handbook.
Q.5 What mileage can I expect out of my new set of tyres?
A. Tyre mileages varies greatly according to the vehicle type, driver ‘style’, different road / weather conditions the tyres are driven in, how they are maintained etc., and is therefore very difficult to predict.
Q.6 What can I do to gain the best life out of my tyres?
A. Many factors have an effect on the life of a tyre, they include:
1. Maintenance of correct inflation pressures is most important.
2. When carrying an extra load, or preparing your vehicle for a trip,
increase the tyre pressure by approximately 28 ~ 42 kPa (4 ~ 6 psi).
Refer to the Tyre Placard for ‘loaded pressure’ information
3. Ensure wheel alignment of your vehicle is accurately maintained.
4. Have tyres regularly rotated
5. Avoid impact damage from such things as potholes, gutters, kerbing.
6. Drive the vehicle carefully. Hard acceleration, braking and cornering will drastically reduce tyre life.
Q.7 What is wheel alignment?
A. ‘Wheel alignment’ is the accurate measuring and precise positioning of the road wheels on your vehicle to ensure the least amount of wear to your tyres. When correctly aligned, the life of your tyres will be significantly extended, your car also should also be easier to steer, handle better, be safer to drive and return improved fuel economy.
Q.8 How do I know when my car needs a wheel alignment?
A. If your car is difficult to keep in a straight line, ‘wanders’ on a straight road, does not ‘self-centre’ after turning corners, or the steering wheel is not straight, it may well require a wheel alignment.
Alignment should also be checked after impact with a kerb or pothole and when tyres are replaced or rotated.
Incorrect wheel alignment will rarely cause a vibration felt through the steering wheel.
Q.9 How do I know when my wheels need balancing?
A. Front wheels out of balance will create a wobble or vibration through the steering wheel, generally, a similar wobble or vibration will be evident through the seat, if the rear wheels are out of balance.
USE of “NITROGEN” instead of “AIR”
Q.10 I have heard a lot about using Nitrogen instead of ordinary air in
tyres, what are the benefits and/or disadvantages, - if any?
A. a The claimed Benefits of using nitrogen instead of air are:
1) Less pressure variation during temperature change.
2) Due to its slightly larger molecular structure, Nitrogen does not ‘bleed’ through the ‘porous’ carcase of the tyre as quickly as air thus maintaining correct pressure longer.
3) Nitrogen is ‘dry’ therefore it does not ‘contaminate’ the interior of the tyre.
4) Being a ‘dry’ gas, Nitrogen also does not contain moisture which expands with temperature increase, thus further increasing tyre pressure.
A. b The suggested Disadvantages of using nitrogen instead of air are:
5) Cost – although offered free on initial tyre fitment in some situations, a charge may be incurred if puncture repair required.
6) Availability – Nitrogen may not be available in all areas when pressure is low or tyre is repaired
7) As a modern tubeless tyre has minimal leakage (for one or two pounds within 1 - 2 months at constant temperature) the cost and inconvenience may not be justifiable.
Q.11 If Nitrogen filled tyres lose pressure, can they be topped up with
ordinary air?
A. 1 Yes, a mixture of air and Nitrogen will not harm the tyre; also the variations in pressure build-up (depending on Air/Moisture/Nitrogen ratio) will not be noticeable under normal driving conditions.
2 In all cases, a mixture of Air/Nitrogen is far safer than running tyres under inflated as this can severely damage the tyre wall and place the car and its occupants at great risk.
CHANGING TYRE TYPE
Q.12 My light commercial vehicle is fitted with Light Truck (LT) tyres
but as I do not carry any loads, can I fit passenger (P) car tyres to improve the ride and performance?
A. No! With all vehicles, the replacement tyre must be able to carry at least an equal load as the original tyre listed on the tyre placard.
Please note: any replacement tyre must be within 15 mm of the Overall Diameter of the original specification tyre.
TYRE VALVES
Q.13 Can I replace the tyre valve on my car with one from another
vehicle?
A. Yes. Currently, the “Schrader” valve is the only component that is
common to every vehicle on the road, including trucks, heavy off road equipment, motorcycles and even most bicycles.
(How long this will last at the current rate of technical advancement is any body’s guess, but Mr Schrader’s valve has withstood the test of time so far.)
RUN FLAT TYRES
Whilst there may be some argument for the use of these tyres in countries with poor security, their adoption in Australia is manufacturer driven, and generally dictated by vehicle production costs.
Q.14 What are the Advantages of Run Flat tyres?
A. 1. Extra boot space as no spare wheel/tyre is carried
2. No spare = Less weight to carry
3. When the warning signal indicates pressure loss, Car can be driven for a limited distance without loss of performance until the tyre is changed
4. Rear bodywork can be made to absorb more of the forces generated in road crashes through the increased ‘crumple zone’ available when the vehicle is designed without a spare wheel.
Q.15 What are the Disadvantages of Run Flat tyres?
A. 1. Initial purchase price higher.
2. The additional cost of a pressure loss, warning system.
3. Generally harsher ride and lower performance.
4. Run Flat Tyres are generally not repairable when punctured.
5. Limited availability of replacement tyres, particularly outside the Metropolitan area.
6. Highly specialised equipment required to change Run Flat tyres
7. When flat, they cannot be used for long distances (over 80-100km).
Q.16 I have run flat tyres on my car. – I recently had a puncture in one
tyre and was told by my tyre person that it cannot be repaired but has to be replaced. Is this correct?
A. Some manufacturers of run flat tyres state they should not be repaired.
Consult your tyre dealer to confirm if they recommend a repair for your particular tyre.
(Refer to search facility on Home page)
Q.17 How much extra will my tyre bill be?
A. About 1/3 extra depending on how many punctures you have. Some brands will not allow the tyre to be repaired, these must be replaced.
Q.18 If I can’t find any where to change it within 80-100k’s, then what?
A. If the tyre is not replaced within the given period, it will be destroyed and the handling will deteriorate rapidly.
Q.19 Do I have any other options?
A. Generally, Run Flat Tyres are not repairable.
Therefore, other than removing the wheel and taking it to a service centre for a replacement tyre, a tow truck would be your only option, provided one is available at that location.
With towing there are three possible options.
1. Motoring Association tow truck to their nearest service point.
2. Contact makers warranty care for provision of a tow truck.
(Flat tyres may not be covered)
3. Call a tow truck at your own expense.
Q.20 Can run flat tyres be fitted to any vehicle?
A. Yes! Run flat tyres can be fitted to normal wheels, but the vehicle must be fitted with a tyre pressure warning system.
Q.21 How can you tell if a run flat tyre is flat?
A. A run flat tyre will not look flat even when it is, but damage occurs internally when driven deflated. This is why it is necessary to have a tyre pressure warning system.
Q.22 How does a run flat tyre perform when compared to a conventional road tyre?
A. The run flat tyre’s performance is similar to a normal road tyre, albeit with a harsher ride.
Q.23 Is the ‘vehicle ride’ compromised when Run Flat Tyres are fitted?
A. The ride may be slightly firmer due to the more rigid sidewall; however; the suspension is generally modified slightly to compensate.
Q.24 Is my vehicle legal in Victoria even though it has no spare tyre?
A. Yes, in Victoria, the spare wheel is not required to be fitted or carried under the Vic Roads Roadworthy Regulations.
Q.25 If one of my run flat tyres is damaged beyond use, can I use a conventional road wheel and tyre in its place?
A. Under emergencies this can be done provided that the overall diameter is compatible.
In this situation, the conventional road wheel and tyre would be treated as a “Temporary Use Spare Tyre” (TUST) - speed limited to 80km/h.
The run flat tyre must be replaced at the earliest possible time and this wheel /tyre assembly remounted to the vehicle.
PLEASE NOTE THIS IMPORTANT INFORMATION:
Where high performance or Run-Flat tyres are fitted.
Be aware that a sensing device can be fitted in either the valve assembly or on the wheel rim itself - usually in the centre recessed section.
If this is the case, ensure this is not damaged as they are very expen$$ive.
Always advise tyre repairers that such a device is fitted to prevent accidental damage.
Some vehicles use the ABS braking system instead of pressure sensors to monitor the inflation state of the tyres.
For further information refer also to the vehicle Owner Handbook
Q.26 If I’m not happy with the run flat idea, what is my alternative?
A. You could fit conventional radial ply tyres, but you should make arrangements to carry a spare somewhere. (Maybe a space saver) or buy a make of car that is provided with a spare.
Q.27 If I have a puncture and my car does not come with a spare tyre could I do anything myself?
A. Yes, if you carry a manual, or battery powered air pump, you can try inflating the tyres. Most punctures create slow leaks, so it may last for enough time to reach a tyre dealer/repairer.
If the tyre won’t re inflate, then back to the previous answer. “Find leak” or similar foam pressure pack repair kit may also help, but bear in mind this is purely a temporary emergency procedure.
Do not ignore the problem or further damage will occur.
Q.28 What if I can’t conveniently find a replacement run flat tyre?
A. You can fit a standard tyre of the same size on the rim as a temporary measure
TEMPORARY USE SPARE TYRES (TUSTs)
Also referred to as space saver spare wheels and tyres
Q. 29 What are those funny looking, undersized, brightly coloured spare wheels?
A. They are called “Temporary Use Spare Tyres” (TUSTs)
Q.30 Are they legal for road use?
A. Some vehicles have insufficient space available to carry a conventional spare wheel and tyre. To ensure continued mobility of these vehicles when a tyre is punctured or damaged, manufacturers provide a temporary-use, space saver spare wheel.
The Vic Roads Roadworthiness Section, Road Safety Bulletin “TESTING TIMES”, April 1995. Issue 1, states:
“Temporary use spare tyres are supplied as standard equipment for some vehicle models throughout Australia and other countries. They can be of several forms including types that are stowed deflated and collapsed within the rim profile with a pressure capsule for inflating them and other types that have a very narrow profile.
Temporary use spare tyres have a legitimate place and are acceptable for use on vehicles but strictly in their intended role, which is as an emergency tyre to enable the vehicle to be driven a reasonable distance to a place where the normal tyre can be repaired or replaced.
These tyres are usually of a lighter construction and less durable than normal tyres and frequently are a distinctive colour. They usually have a lower speed rating than normal tyres and the vehicle should be driven within this limit when the tyre is fitted.
Extended use of the tyre is not acceptable and a RWC should not be issued to a vehicle with one fitted to a road wheel.”
Q.31 Are all Temporary Use Spare Tyres the same?
A. There are two types of TUSTs or ‘space saver’ spare wheels.
1. The more common of these is a wheel and tyre assembly with a narrower width.
2. The second type is one incorporating a special tyre which, when not in use, is carried deflated (collapsed) on the rim occupying much less space than a conventional tyre. These are also narrow tyres.
Q.32 Why are these “TUSTs” only suitable for temporary use?
A. The, strength and durability of narrow space saver spare tyres are inferior to conventional tyres. The rubber compound used is generally softer to simulate traction capabilities of the other ‘road’ tyres and this drastically reduces the service life of the TUST
Q.33 Why are they limited to 80km/hr when used?
A. With dissimilar tyres fitted, the handling and controllability of your vehicle can become unpredictable. Vehicle manufacturers design their space saver wheels and tyres to compensate for any imbalance so you should only use space savers that are supplied or recommended by the manufacturer of your vehicle.
Q.34 How long may I leave a TUST on my car?
A. Space saver wheels and tyres must only be used in emergency situations and driven on for as short a distance as possible.
When your damaged wheel or tyre is repaired, you should put it back on the vehicle immediately.
One of the contradictions of the concept of TUSTs, is that as a general principle, the best tyre possible should be maintained as the spare.
When it is required, that is all you have – there is no “back-up” spare
For this reason, many consider them particularly inappropriate for use in regional areas.