Oil Changers

Servicing Tips - Safety

Know Your Towing Limits

2016-05-09 10:14:03

Some drivers figure that anything they can attach to their towbar can be towed by their vehicle. Nope. If you're going to do any towing you should be aware of safety issues, New Zealand towing laws, and potential liability.

Understanding tow ratings is important for safe towing. A tow rating is the weight limit that your vehicle can safely tow. The manufacturer calculates the tow rating for every vehicle, but different options on the vehicle can affect that rating. As a driver you need to read the towing section in their owner's manual to get the specific tow rating for the vehicle they own.

Your trailer hitch also has a weight limit, and it may not match the tow rating for your vehicle. Your vehicle may be rated for 2,500 kgs, but if you have a 1,000 kg towbar rating  you shouldn't be towing more than 1,000 kgs. If you tow a 2,000 kg trailer on that hitch, it could break free and you would be liable for any resulting damages.

Another example, one popular SUV has a tow rating of 3,500 kgs, but in the owner's manual, it specifies that a sway control device be used for trailers weighing over 1,000 kgs and that a weight-distributing hitch is required for trailers over 2,500 kgs. If the vehicle owner tows a 3,000-kg trailer without a weight-distributing hitch and ends up in an accident, the owner will be held liable as they didn't comply with the vehicles towing requirements.

Vehicle owners also need to keep in mind that tow weights include the weight of passengers and cargo inside the tow vehicle. So if your tow rating is 3,500 kgs and you're carrying 300 kgs of passengers and cargo, you can only tow a trailer weighing up to 3200 kgs.

Two numbers that drivers should be aware of are the Tare Weight and the GVM. These codes are usually imprinted on the inside of the driver's side door. GVM stands for Gross Vehicle Mass and is the weight of the vehicle itself including any cargo, passengers, fuel, etc. The Tare weight is the weight of the vehicle when empty (ie no cargo or passengers). Take the GVM and subtract the Tare weight of the vehicle and you have the maximum weight the vehicle can safely carry in passengers and cargo. 

Most trailers also have these weights and are subject to maximum loads as set out by the manufacturer. When working out how much you can safely tow with your vehicle you need to allow for any weight that may be going onto your trailer ie Bikes, food, etc that you may take away in your caravan on holiday.

This may seem a bit complicated, but you ignore these ratings at their own peril. If you haul or tow loads over the maximum ratings you can be liable in event of an accident.

New Zealand law requires that safety chain/s be attached when towing a trailer. Some may require trailer brakes as well if the trailer is over a certain weight limit. Others mandate trailer brakes only in certain situations. If you are going to tow a trailer, you should find out the local laws regarding trailer brakes, hitches, as well as weight and length restrictions.

To tow safely, you also need the proper tyres on the tow vehicle. Tyres need to be in good condition, with adequate tread, and they need to have a load rating high enough to handle the weight of the trailer. 

Your owner's manual is your primary source for auto advice regarding towing since it is specific to your vehicle. Be sure to read it carefully before doing any towing, and as always keep your preventive maintenance up-to-date and practice good car care to ensure the safety of your vehicle on the road—especially when pulling a trailer.

Oil Changers
PO Box 16686 Hornby
New Zealand 8441
03 3442374