tyretips

TYRE MAINTENANCE

 

Inflation Pressure

The tyres on your vehicle are responsible for transmitting all steering, driving and braking forces from your vehicle to the road. Poor inflation pressure maintenance can compromise your car’s performance and therefore your safety. Regular tyre pressure checks will also minimise the cost of motoring by improving fuel consumption and tyre life. Check your vehicles tyre placard for your vehicles recommended tyre inflation pressures.

 

Why is maintaining tyre inflation pressure important?

  • Tyre inflation pressures naturally decrease with time as air slowly bleeds through the tyre’s inner liner. For this reason, tyre inflation pressures need to be checked and adjusted at regular intervals.
  • Correct tyre inflation pressures are essential for optimum tyre grip. Under-inflation (inflation pressures that are lower than recommended), and over-inflation (inflation pressures that are higher than recommended) both compromise tyre grip.
  • Correct tyre inflation pressures optimise tyre life.
  • Under-inflation increases the rolling resistance of the tyres and therefore, vehicle fuel consumption. Inflation pressure maintenance will minimise vehicle fuel consumption.
  • Tyre inflation pressure checks can reveal punctures and other tyre damage that need attention from your Toyo tyre dealer.

 

When do tyre inflation pressures need to be checked and adjusted?

  • Inflation pressures need to be checked and adjusted when the tyres are cold, before the vehicle is driven.
  • Inflation pressure checks every 2 weeks is considered optimum, every 4 weeks could be considered a maximum interval between inflation pressure checks.

 

Where do I find the recommended tyre inflation pressure for my vehicle?

  • The vehicle’s tyre placard will include the vehicle manufacturer’s tyre inflation pressure recommendations. On most vehicles the tyre placard can usually be found in the driver’s door jamb. On some vehicles the tyre placard may be in the glove-box, under the bonnet or behind the fuel filler flap.
  • The vehicle owner’s handbook usually includes the vehicle manufacturer’s tyre inflation pressure recommendations. Contact the tyre manufacturer for their inflation pressure recommendations.
  • Keep in mind that if you have fitted a tyre size to your vehicle that is different from the original equipment tyre size, the tyre recommendations on the vehicle’s tyre placard and in the owners handbook may not be suitable.
Example of vehicle manufacturer’s tyre inflation pressure recommendations

Inflation Pressure Tips

Tyre pressure gaugePurchase a high quality pressure gauge. This is a one-off purchase that will provide accurate pressure readings for several years or more.

If your vehicle is heavily laden, higher inflation pressures are recommended compared to when the vehicle is lightly loaded. Don’t rely on the appearance of the tyre to “guess” the pressure, use a gauge. There is only a small difference in the appearance of low profile tyres when the inflation pressure is suitable and when the tyre is under-inflated.

Tyre rotations for passenger cars, SUVs and light commercial vehicles

Regular tyre rotations are recommended to maximise tyre life. Most car manufacturers recommend tyre rotations as per the car owner’s handbook and/or as part of regular servicing.

Tyre rotations are especially important to maximise tyre life on front-wheel-drive cars. In these cars, tyres fitted to the front axle typically have wear rates that are 2 to 2.5 times faster compared to the wear rate for the rear tyres.

For most cars, tyre rotations are recommended every 10,000 running kilometres, or as per your vehicle owner’s handbook recommendation.

Tyre rotations are also an opportunity for your tyre specialist or motor mechanic to check & adjust tyre inflation pressures and inspect the tyres for irregular wear. This may indicate that wheel alignment needs adjustment and suspension components can be inspected for wear.

Diagonal rotations are recommended for non-directional and asymmetric tyres, as shown below. This is the preferred method of rotation due to the fact that the passenger’s side front tyre is the fastest wearing tyre on most cars, SUVs and light commercial vehicles. A diagonal rotation will reverse the direction of rotation of the tyres. Reversing the direction of rotation of non-directional or asymmetric tyres will not damage the tyres.

Tyres with directional tread patterns should be rotated from the front to the rear axle only, as shown below. Rotating directional tyres diagonally will reverse the direction of rotation, which should be avoided. Reversing the direction of rotation of directional tyres reduces the tyre’s resistance to aquaplaning.

NON-DIRECTIONAL OR ASYMMETRIC TYRES

NON-DIRECTIONAL OR ASYMMETRIC TYRES

DIRECTIONAL TYRES

DIRECTIONAL TYRES

Balance

You may have noticed the small weights attached to your wheels. These weights are placed on your wheels when new tyres are fitted in order to balance the wheel & tyre assembly and eliminate vibration that may cause ride disturbance as well as ensure optimum tyre performance and wear qualities. Where you are experiencing ride disturbance due to vibration, contact your Toyo tyre dealer to determine the cause.

Wheel Alignment

Correct wheel alignment is essential for optimum tyre performance and life. Poor wheel alignment can compromise car handling, tyre life and fuel consumption.

Toyo recommends your car's wheel alignment is checked periodically, or whenever irregular tyre wear is evident, whichever comes first.

A wheel alignment can also identify any other vehicle suspension problems that may need attention or repairs. Most Toyo tyre dealers can perform vehicle wheel alignments.

Tyre Inspection

At least once a month, closely inspect your tyres for signs of tyre damage such as cuts or punctures as well as uneven or excessive wear.

When inspecting your tyres, you should also look for any stones, bits of glass, metal, or other foreign objects in the tread or sidewall. These may work themselves deeper into the tyre and cause air loss. If any tyre continually needs more air, have your Toyo tyre dealer check to find out why it is leaking. Damage to the tyre, wheel, or valve may be the problem.

CARAVAN & MOTORHOME TYRE ADVICE

 

Specification and inflation pressure - Toyo Tires H08

 

KEY POINTS

  • The rear axles of single-wheel axle motorhomes are vulnerable to over-loading with possible subsequent tyre failure due to the potential for users to inadvertently place excessive load items in the vehicle without realising they have exceeded the stipulated gross vehicle mass
  • Rated vehicle Gross Vehicle Mass (GVM) are often not indicative of the actual loaded vehicle weights
  • Excessive heat generated by flexing from excessive load and/or incorrect tyre pressure damages the bonding between tyre components and can result in in-service failure
  • Due to the nature of how they are used, motorhomes require precise tyre pressures determined by weigh bridge readings. This is critical for single rear-wheel axle motor homes
  • Toyo Tires H08 product is the most common product used for fitment to caravans / motorhomes
  • Contact Toyo Tires technical manager Steve Burke for assistance on sburke@toyo.com.au, (02) 8796 0271 or 0407 235 150

 

THE ISSUE

Any tyre failure has serious consequences – placing vehicle occupants and road users in potential danger.

Over-loaded tyres generate excessive heat due to increased flexing. Over time, excessive heat damages the bonding between the tyre components. This creates the potential for tyre disintegration in service.

When loaded, the actual weight of caravans and motorhomes can exceed the vehicle’s factory rated GVM. On motorhomes with single-wheel rear axles where there is excessive loading, the rear axle load is usually problematic, with some vehicles having rear axle loads greater than the manufacturer’s maximum ratings. For this reason rear tyres are most prone to failure due to over-loading / under-inflation.

THE SOLUTION

To determine suitable tyre inflation pressure, correct loaded axle weights are required. Each axle must be individually weighed on a weigh bridge, when the vehicle is fully loaded.

With this information, accurate cold tyre inflation pressures can be determined. If you are uncertain about inflation pressures please contact Toyo Tires technical manager Steve Burke with an accurate GVM for a technical recommendation. 

Recommended cold inflation pressures will provide a safety margin, which is standard engineering practice. Safety margins also take into consideration the fact that when in service tyres will often have loads (dynamic loads) that are much higher than those measured on the weigh-bridge (static-loads), due to factors such as road camber and weight transfer.

WHAT TO DO WITHOUT WEIGH BRIDGE READINGS

Where tyre dealers are fitting tyres to caravans and motorhomes or on loose wheels in the absence of recent weighbridge results or tyre manufacturers recommended inflation pressures, it is recommended that tyres are inflated to the maximum rated inflation pressure.

Tyre dealers have a responsibility to ensure that tyres they supply are inflated to the correct pressure and that the consumer is aware of the correct pressures for their vehicle/application.

For tyre dealers, taking this course of action is the most effective way of preventing tyre fatigue or failure due to under-inflation. It is highly recommended to tyre dealers that caravan and motorhome users weigh-bridge their vehicles when loaded to ensure actual tyre loadings are known, and all steps are taken to prevent tyre over-loading.