Over the past few years there have been many changes in vehicle design. In most cases these have provided greater reliability and improved fuel consumption. Unfortunately the characteristics required for towing have usually not been enhanced. Most vehicle owners hand books state that vehicles are primarily designed for as passenger vehicles and not for towing. Motorists should appreciate these limitations so that their vehicle dose not suffer structural damage due to the use of incorrect towing equipment of excessive loads.
In 1989 Australian Design Rules (ADRs) were introduced which affect the construction and towing of trailers, including caravans. Currently there are no towing regulations which specifically refer to 'caravans' The ADRs include the requirement for plates on trailer drawbars which amongst other information states the aggregate, or maximum, mass of the trailer and data on the towbar which indicates the rating of that towbar. It should be noted that ADR 62 states that the rated capacity of the towbar shall not exceed the vehicle manufacturer recommendations. Below is a summary of the rules relating to towing weights which should assist in the selection of towing equipment and/or caravan and the towing speeds applicable to various states.
While there are some variations in the Road Traffic Regulations in different States, most agree on the following safety aspects:
The trailer must not be bigger or heavier than the driver can safely control,
The total or laden mass of the trailer must not be more than:
- the maximum mass (A.T.M.) determined by the trailer manufacturer and as stated on the trailer plate,- the load rating of the trailer's coupling of the towbar fitted to the towing vehicle,- the total load rating of all the trailer's tyres.
The combination of tow vehicle and trailer must be properly set up. This means that there is a load of about 10% of the total trailer mass on the towbar and that the outfit has a level attitude. Generally this necessitates the use of a load distributing device.
Exceeding the maximum towing load as recommended by the towing vehicle manufacturer can:
Invalidate warrantyNullify insurance, andEffect long term vehicle safety and reliability.
National Towing Regulations
In December, 1998, agreement was reached by all State Ministers of Transport to implement National towing regulations.
In essence, the National rules state that: A motor vehicle with a Gross Vehicle Mass (G.M.V.) not exceeding 4.5 tonnes must not, without the approval of an authority, tow a trailer with a mass (including any load) exceeding;
The capacity of the towing apparatus fitted to the vehicle, or
A relevant maximum trailer mass specified by the vehicle manufacturer.
Put simply, the most you can tow is the amount specified by the vehicle manufacturer of the capacity of the towbar - WHICH EVER IS LEAST.
If you want to know how much your vehicle can tow, firstly check the owners manual or vehicle sales brochure for the manufacturer's towing recommendations. Secondly make sure that the towing capacity is as least as much, if not more, than the mass of the trailer, including its load. If you are unsure how strong the towbar is, have a chat to a reputable towing equipment specialist.
In the case where a motor vehicle manufacturer has not specified a maximum towing mass, the limit is stated to be:
1.5 times the unladen or kerb mass of the motor vehicle if the trailer is fitted with brakes; or
The unloaded mass of the motor vehicle if the trailer is not fitted with brakes.
It should be noted, however, that the above will rarely apply as apart from using a truck, just about every vehicle that is likely to be used for towing a caravan, boat trailer, horsefloat or similar has a manufacturer's towing recommendation.
Owners of 4WDs and light commercial vehicles should also be careful that they do not exceed the Gross Combined Mass (G.C.M.) of the vehicle. The GCM refers to the maximum vehicle plus its load, including a trailer, is permitted to weigh. It is possible that when a motor vehicle is loaded with, for example, five adults, their luggage and camping gear that the maximum allowable trailer mass has to be reduced so as to not exceed the GCM.
While this may sound a little confusing, it is important that this is considered so as to not void the warranty or insurance.
Speed Limits When Towing:
Open road speed limit.
Please note that the normal open road speed limit is 100km/h unless sign posted otherwise.
Normal sign posted speed limits apply.
ACT, New South Wales, Queensland, Victoria & ACT:
As for South Australia.
In Tasmania all vehicles towing trailers or caravans must abide by the posted speed limit, unless the trailer or caravans has a GVM of 12 tonnes or more. Highways in Tasmania have speed limits of 100km/h and 110km/h. Therefore the driver of a vehicle towing a trailer or caravan can drive at the posted speed as long as it is safe to do so.
100 km/h when towing a caravan or trailer..
Safe speed for prevailing conditions on the open road.
Motorists should remember that in some cases motor vehicle manufacturers place speed restrictions on a vehicle when towing over a certain mass. Ford only permits 100km/h if the load is less than 1200 kg. At 1600 kg this drops to 90km/h. The speed further reduces until at 2300 kg, 80km/h is the maximum. Holden takes a similar approach but also ties the vehicle speed to the type of towing equipment fitted. Spending a few minutes reading the trailer towing section in the owners manual is highly recommended.
Another area of concern involves the fitting of other than original towing equipment, particularly where the car manufacturer has a 'towing package'. Examples are the current model Commodore rated at 2100 kg towing capacity and the Falcon which is now rated at 2300 kg.
In the cases of the Commodore there are up to 15 items that make up the towing pack. Ford's list somewhat fewer for the Falcon. Simply fitting a 2100 kg towbar to the former or 1 2300 kg to the latter does not automatically upgrade the vehicles to the respective capacity recommended by the manufacturer.
In this case manufacturer's warranties could well be considered void if some damage was caused to the vehicle and it was discovered that the other required items has not been installed. Included in these are special brake pads for Falcons and underbody heat shield on the Commodores.
The above doesn't mean that it is always necessary to fit genuine equipment. It is important, however, to consult someone experienced in towing equipment to ensure that the correct equipment is chosen and fitted.
Reproduced courtesy of Tom Olthoff of 'Caratech Consultants' & 'Caravan World Magazine'.
Graphics supplied by 'Hayman Reese' & 'Mitsubishi Motors Australia Ltd'.