Aggregate Trailer Mass (ATM)
The total laden weight of the trailer, including the weight of whatever you’re carrying and the weight imposed on the tow ball by the trailer’s coupling. This means that the ATM will be the GTM (see below) plus the weight on the tow ball.
ATV Trailer
Trailer designed for transporting all-terrain vehicles (ATVs) such as quad and motor bikes.
Box Trailer
The term for any open top trailer with sides.
The coupling is the link that joins your trailer to the towing vehicle. There are different types depending on the weight you’re hauling and whether you want to take it adventuring off-road or just around town.
Drawbar
The V-shape portion of the trailer that extends forward from trailer frame. Includes the coupling.
Gross Combined Mass (GCM)
The gross combination mass (GCM) is the maximum allowable combined mass of a road vehicle, the passengers and cargo in the tow vehicle, plus the mass of the trailer and cargo in the trailer. This rating is set by the vehicle manufacturer. Sometimes called the gross combination weight rating (GCWR), gross combination mass (GCM), gross train weight (GTW), or maximum authorised mass (MAM).
Gross Trailer Mass (GTM)
This tells you how much weight the trailer can carry fully loaded. Unless you’re towing heavy cargo, all you really need to know when you buy a trailer is that if its GTM is 750kg or less, it is not required to have brakes.
Gross Vehicle Mass (GVM)
The gross vehicle mass (GVM) is the maximum operating weight/mass of a vehicle as specified by the manufacturer including the vehicle's chassis, body, engine, engine fluids, fuel, accessories, driver, passengers and cargo but excluding that of any trailers.
Motor Vehicle Licensing
The payment of a fee to use your vehicle on public roads. The fee helps to pay for roading projects and road safety programmes. Often referred to as ‘rego’, but should not be confused with vehicle registration.
Numberplate Light
Light fitted to the rear of a trailer to illuminate the numberplate when travelling at night. Tail lights often have a numberplate light built into them.
Open or Enclosed Trailer
This refers to whether the trailer is open or covered.
Registration
The process by which a vehicle’s details are added to the Motor Vehicle Register and its number plates are issued.
These chains keep the trailer connected should the coupling disengage with the hitch ball.
Single Axle
This trailer has one axle attached either via the springs or directly onto the trailer bed with clamps or supporting hardware. It’s light, easy to tow and generally cheaper than a tandem axle trailer. Single axle trailers are ideal for light towing jobs.
Tare Mass
This is the weight of the trailer when empty. This will be stamped on trailer by the manufacturer.
Tandem Axle/ Dual Axle/Double Axle
Tandem trailers have two axles placed in close proximity to help disperse the weight load of the cargo. They tend to be designed to carry heavier loads, be more stable and have better suspension than single axles, which provides smoother towing.
Tie-down Points
Any load you carry will need to be securely tied down. Built-in tie-down points recessed into the trailer floor can be a bonus if you regularly haul heavy items such as motorbikes.
Towbar
The bar on the rear of a vehicle to which a trailer can be attached to pull it or be pulled. All vehicle drawbars are rated to a certain weight. Check this rating before towing a vehicle – towing an unbraked trailer exceeding this rating could not only land you in trouble with the law, it could also result in a serious accident.
Weight Distribution Hitch
Also called a ‘level ride’ or ‘load leveller’, this prevents your car from sagging when the trailer is connected by evenly distributing weight across all wheels of the towing vehicle and trailer.
Weight Rating
Each trailer will have a maximum weight it can carry legally.
WOF
A Warrant of Fitness (commonly known as a WOF) is an official New Zealand document certifying that a light motor vehicle has passed a compulsory periodic inspection of safety and roadworthiness. Usually are compulsory for any vehicle with a gross mass of less than 3500kg.
