RV FEATURE
TYRE LOADS
For load-sharing suspension systems , the maximum legal individual tyre load equals the GTM rating divided by the number of tyres fitted to the van .
The individual tyre load , when the van is empty , equals the Tare mass minus the empty ball loading divided by the number of tyres fitted to the van .
If the recommended maximum vehicle operating speed is less than 120km / h , it should say , “ The tyres fitted to this vehicle shall have a speed category at least equal to the recommended maximum vehicle operating speed , ‘…’ km / h .”
In this case , ‘…’ is the vehicle manufacturer ' s recommended maximum vehicle operating speed . It is not permitted to state any specific tyre manufacturer ' s name or brand .
The tyre load rating must be stated in kilograms and the tyre inflation pressures must be stated in kPa ( not psi ).
For non-load-sharing suspension systems ( on tandem-axle vans ), the front and rear tyres will have different loadings , if the van is not level ( in a side view ).
For maximum traction and tread life , the loading needs to be spread evenly across the full width of the tread .
This can only be achieved if the correct inflation pressure is used , so that the tread is at the same temperature across its full width . The use of a tyre pyrometer is really the only efficient way of checking this .
It is essential that caravan buyers fully understand all of the information that is provided by the manufacturer on the tyre placard , before they accept the caravan , in order to avoid possible problems in the future .
If you have any questions about any items on the tyre placard , it is important to have the dealer provide a credible explanation .
You can also ask a tyre specialist if you have any questions regarding the tyres fitted to your van , or if they can recommend a better tyre .
All relevant tyre and permitted wheel specifications are listed in the Tyre and Rim Association of Australia ' s Standards Manual – visit www . tyreandrim . org . au
If the van has a tunnel boot , this is where you ' ll typically find the placard containing the mandatory tyre information .
/ 15