How much is your vehicle designed to carry or tow?

Finding how much your vehicle and trailer are legally and safely allowed to tow or carry is crucial to safe driving. Here’s the different weights you need to know. 

• Tare Mass or Weight - this is the weight of your standard vehicle when it’s completely empty, except for all its fluids, such as coolants and oils, and 10 litres of fuel in the tank. 
• Kerb Mass or Weight - this is similar to the Tare Mass of your vehicle, but with a full tank of fuel and no accessories, like bull bars or roof racks, for example. 
• Gross Vehicle Mass (GVM) or Weight (GVW) - this refers to the maximum weight of the vehicle itself, including its passengers, cargo, and accessories, but excluding any trailers or towed vehicles as specified by the manufacturer. You can usually find out your GVM on the inside of the driver’s door, or via the owner’s manual. 
• Payload - this is the maximum load your vehicle can carry. You find your payload out by deducting your Kerb Mass from your GVM, and that number will tell you how much stuff you can load into your vehicle. 
• Gross Vehicle Axle Mass or Weight - this refers to the maximum weight that your front vehicle’s front and rear axles can carry. 
• Tare Trailer Mass or Weight (TARE) - this is how much an empty trailer weigh. Trailer can refer to anything you can tow or ‘trail’ behind a vehicle, such a single-axle box trailer, all the way up to multi-axle caravans. 
• Gross Trailer Mass (GTM) or Weight (GTW) - as determined by your trailer’s manufacturer, this is the maximum axle load that your trailer is designed to carry.
• Tow Bar Download (TBD) - you need to make sure that your tow bar is designed to suit your vehicle and its towing capacity. Your TBD should be around 10-15 percent of the Gross Trailer Mass (GTM). You can use this formula to determinewhat’s safe for your vehicle: TBD divided by GTM multiplied by 100. That will equal the safe percentage of your GTM. 
• Aggregate Trailer Mass (ATM) or Weight (ATW) - this the Gross Trailer Mass (GTM) combined with the Tow Bar Download (TBD).  
• Gross Combination Mass (GCM) or Weight (GCW)- When you’re towing a trailer, you need to find out your Gross Combination Mass (GCM). This is the total weight of the vehicle and trailer combined, as specified by the tow vehicle's manufacturer. It takes into account the maximum weight of the vehicle, the maximum weight of trailer, plus any additional load being carried by both the vehicle and the trailer. 

Choose the right attachment

There are a few different options for attaching a trailer to your vehicle, including a tow ball and hitch, a tow bar, and a fifth-wheel coupling. The best attachment for your vehicle will depend on the size and weight of the trailer and your vehicle’s towing capacity.  

• Tow ball - these are the most commonly used hitch type in Australia because they’re cheap and easy to use, and will work pretty well for the majority of applications. However, because they don’t move up, down or side to side freely with your vehicle, they aren’tgenerally suited for going off-road. This attachment is suitable for small to medium sized trailers. 
• Treg or trig hitch - these hitches are fully articulating in both directions, but they can be difficult to hook and detach by yourself, or on soft or sloping ground. Despite this, these hitches are great for off roading with small to medium sized trailers. 
• Fifth wheel coupling - if you have a ute, you have the option of installing a fifth wheel coupling. These hook into the tray, tub or bed of your ute, and are towed just above the rear axle instead of a tow bar. These obviously aren’t suitable for vehicles that don’t have a tray, but are great for pulling very large trailers and loads if you have the option.  

Secure your load

Properly securing your load is essential for safe towing. Tying down your load not only helps stop your belongings flying off during the journey, but it also stops your load from moving around and getting damaged. Once you’ve evenly distributed the weight of your load across the box trailer, there’s a few different methods for making sure your load is secure.  

• Ropes - good quality rope that can handle alot of pressure is great for securing your load. By tying the rope to the d-rings or cage bars of your trailer, you can tie your items down and stop them from moving around during your journey.  
• Ratchet tie downs - these are straps that have fasteners that are used to tighten everything down. There are two types, loop straps and two-piece straps. They are great if you aren’t confident with knot tying. Like when you’re using rope, make sure the tie downs you use can handle the weight of your load. 
• Tarps - these are a great option for when you’re using your trailer in wet weather. Tarps can usually be tied to your trailer via fasteners on the corners, or you can use a rope. 
• Nets - like tarps, nets cover your entire load, but you can still keep an eye on your items while travelling. They have hooks and fasteners that can be tied to the d-rings or cage bars of your trailer.   

Check your lights and brakes

Before hitting the road, be sure to check that all of the lights on your trailer are functioning properly. This includes the brake lights, turn signals, and running lights. It’s also a good idea to check the brakes on your trailer to ensure that they are in good working order. If your trailer is equipped with electric brakes, be sure to check the wiring and make sure it’s properly connected to your vehicle. 

Follow the rules of the road

There are a few additional regulations to keep in mind when pulling a trailer. Alongside adhering to the additional road rules, drivers towing a trailer should be aware of any size and weight restrictions for the roads you will be travelling on. When towing with a trailer, it’s also important to allow more space than you normally would between you and the vehicle in front of you, as it will take longer to stop with the added weight behind you. It’s also a good idea to use lower gears when going up hills to help maintain control of the trailer. 

Pulling a trailer can be a great way to transport large or bulky items, but it’s important to make sure you’ve done the preparation and taken the proper safety measures before you head out and while you're on the road. By determining your GVM, choosing the right attachment, securing your load, checking your lights and brakes, and following the rules of the road, you can ensure a safe and successful journey. 

To find out more about NRMA Car Insurance, simply call us on 132 132 to get a quote or find us online 24/7 at nrma.com.au.

All content on The Hub is intended to be general in nature and does not constitute and is not intended to be financial or professional advice. This general advice does not take into account your individual objectives, financial situation or needs (“your personal circumstances”). Before using this advice to decide whether to purchase a product, you should consider your personal circumstances and the relevant Product Disclosure Statement and Target Market Determinations available from nrma.com.au