by Collyn Rivers
Caravan Declared Mass
A caravan‘s Tare Mass is legally its weight when ‘ready for service’ as it leaves its maker. That weight, recorded on a Compliance plate is often incorrect. This article explains why RV Books states: Do Not Trust Caravan Declared Mass.
Most caravan makers produce basic units. The weight of that basic unit is usually declared as its tare mass. This may not, however, be its tare mass when sold. This because caravan makers have dealers install all ‘optional extras’. Jayco is a rare exception. The company installs all optional extras – then weighs each product. Their declared tare mass is correct.
Dealers rarely (if ever) then update the tare mass. The caravan may thus be heavier than declared. That reduces the weight that it may legally carry.
Do Not Trust Tare Mass – it affects its payload.
The most a caravan may legally weigh on a public road is called its Aggregate Trailer Mass (ATM). It is the caravans true tare mass plus its payload.
A caravan‘s payload includes water, LP gas, extra batteries, food and all personal belongings. Set by the caravan maker, payload is usually the most the caravan‘s tyres and suspension legally allows
With rare exceptions, declared tare mass is unlikely correct. The law, however, relates to what the tare mass actually is.
How much payload is provided?
There is no legally required caravan payload. Makers typically provide you with 250 kg (550 lb) for caravans under 1500 kg (3300 lb). Those heavier may have 250-350 kg (550-775 lb). A few makers provide the payload you require. This may cease as forthcoming rules require caravan makers to register their products. You cannot then later modify them.
When ordering a caravan insist the vendor establishes its weight. Include the exact options and accessories you’ve ordered. Plus the weight of water, LP gas etc. Insist the result be included in the purchase contract. And that meeting such weight is a condition of purchase. Prior to final payment, insist on the caravan being weighed in your presence. Check that the batteries, gas bottles, mattresses and drawers etc. have not been removed for weighing.
Weighbridge scales have known margins of error. The errors are, however, within plus/minus 10 kg (22 lb). If the caravan exceeds its declared tare mass by much more than that. Do not take delivery until it is somehow reduced.
Do Not Trust Declared Mass
Never trust the tare mass on the caravan‘s compliance plate. Until its true tare mass is known you do not know that caravan‘s actual payload You can only establish via a certified weighbridge. Include in the buying contract that you will not finalise paying until you have checked that weight.
Weighbridges in Australia are displayed at: https://publicweighbridgeaustralia.com.au/weighbridge-locations/
Many owners underestimate their caravan‘s weight. Furthermore, police report that almost 80% (of RVs checked) are overweight. Moreover, one was over by 400 kg! See https://rvbooks.com.au/overweight-rvs-a-police-point-of-view/