How much can your vehicle tow safely?
This guide is for cars, vans, station wagons, utes, 4-wheel drives and light trailers (vehicles whose maximum laden weight is less than 3.5 tonnes) or load weights less than 500kg.
For trucks, heavy trailers or loads of more than 500kg, refer to:
The official New Zealand truck loading code [PDF, 4.1 MB]
Most vehicles have tow ratings given to them by the manufacturer specifying the gross trailer weight braked, unbraked, or both, that the vehicle can safely tow. Although the law does not require these tow ratings to be followed, the NZ Transport Agency recommends that they be taken into account.
In addition to the requirements above, the law requires that every light vehicle and trailer combination must be capable of stopping within a distance of seven metres from a speed of 30km/h. In effect, this means that the maximum allowable weight of an unbraked trailer is limited by the weight and braking ability of the vehicle being used to tow it.
The Transport Agency recommends, as a guide, that the laden weight of an unbraked trailer should not exceed three quarters of the unladen weight of the towing vehicle and then only if the towing vehicle’s brakes and tyres are in excellent condition. A trailer heavier than this may prevent the vehicle combination from meeting the seven metre from 30km/h brake performance requirement. To illustrate the increase in stopping distance when towing an unbraked trailer, consider a trailer with a laden weight equal to the weight of the towing vehicle.
This combination can be expected to have double the stopping distance of the towing vehicle alone, and even a towing vehicle with good brakes is likely to fail the legal brake performance requirement of seven metres from 30km/h. If the trailer is equipped with brakes, it may be possible to safely tow a trailer heavier than three quarters of the unladen weight of the towing vehicle, but the seven metres from 30km/h brake performance requirement still applies.
Remember, too, to check the tow rating of the tow bar itself. It may differ from the tow rating of the vehicle itself.