By Shell on Aug. 12, 2020
Get it wrong and you can end up in some scary and even life-threatening outcomes, as illustrated by dash-cam footage the world over.
How do you ensure you’re properly prepared and doing it safely? Here are some things you need to know.
The numbers game
Without knowing some key figures and doing the sums, you’re essentially flying (or towing) in the dark.
First, you need to establish your car’s maximum towing capacity – look in your owner’s manual. There will be different numbers for ‘braked’ and ‘unbraked’ trailers, so make sure you pick the right one.
Second, you need to know the weight you’re towing. If it’s a caravan or trailer, remember you won’t be towing it at its tare (unladen) weight, so factor in the necessary extra kilos.
Ideally, your car’s maximum capacity should exceed the towing weight by about 20 per cent. If your car has a 3,500kg rating, for example, you really don’t want to be towing much more than 2,800kg. Why 20 per cent? Because towing ratings are maximums and a safety margin is recommended.
But wait …
You also need to ensure your car’s maximum tow ball download (TBD) is sufficient. This relates to the force pushed onto the tow ball, which is about 10 per cent of the weight being towed. Most cars will have a TBD rating that adheres to this rule (350kg TBD, 3,500kg maximum capacity) but in some it can be proportionally smaller, limiting what you can tow.
Have a think, too, about whether you’ll be loading up your car. If so, you need to know your car’s maximum gross vehicle mass (GVM) and gross combination vehicle mass (GCVM) numbers. The former is the maximum allowed weight for your vehicle, the latter is the maximum allowed weight for your vehicle and a trailer.
Double-checking these numbers is vital because a maxed-out GVM often dictates a reduced maximum towing capacity and a fully loaded vehicle and trailer can easily exceed the GCVM.
Here’s a handy diagram to help keep all those numbers and acronyms straight: