Caravan towing weights and tow vehicle weights. What do they mean?
Overweight towing is illegal, and towing incorrectly can have some severe consequences for both you and other road users. Even highly skilled drivers can get into accidents. A proper understanding of your towing weights is crucial because if you’re overweight, you are liable. Some consequences for towing incorrectly include;
Insurance companies will not cover you.
Towing overweight is against the law.
Incorrect loading can cause your caravan to sway and put lives in danger.
You can damage your tow vehicle’s motor, tow bar, and other running gear.
You could be fined and have your caravan towed away.
Before buying your new Regent Caravan, you should know the towing capacity of your tow vehicle and understand how caravan towing weights work and are calculated. If you haven’t towed before, the new terminology (GTM, Tare, GVM etc.) can be confusing,
We have put this guide together to help caravan buyers navigate the market and buy the right van for their tow vehicle, or buy the right tow vehicle for their new caravan.
And you can start with…
Your tow vehicles towing specs
A towing capacity is established by the tow vehicle manufacturer. The key weights are:
• Gross vehicle mass (GVM), • Gross combination mass (GCM), • Maximum tow ball mass (TBM),F • Tare weight, • Kerb weight (KW), and • Towing capacity.
With these specifications, you can work out your maximum payload and how much you can tow.
To find these weights, occasionally, you’ll find a stamp inside the doorframe of your car with the tow ball weight and towing capacity. Your owner’s manual will have most of the information you need. If you need to search online for your towing capacity, be careful you look at the correct variant of your tow vehicle.
When in doubt, or you have lost the owner manual, get the information directly from the tow vehicle manufacturer or dealership, or even check www.redbook.com.au
Caravan towing weights
A compliance plate is fixed to every caravan built by the caravan manufacturer. Stamped on the compliance plate is the gross trailer mass (GTM), aggregate trailer mass (ATM), tow ball weight when empty, and tare weight of the caravan.
Generally, the compliance plate is either inside the front or tunnel boot of the caravan.
If you’re unsure what the weights of your caravan are or having trouble finding the compliance plate, contact your nearest
Regent Caravans dealer.
What is your vehicles towing capacity?
Your vehicle’s towing capacity refers to the maximum weight your tow vehicle can legally tow. The caravan you tow should have an aggregate trailer mass (ATM) of equal to or less than your towing capacity. All Regent Caravans are fitted with an electric brake controller.
Braked towing capacity
You must have a working brake controller installed on your towing vehicle and caravan. This rating in your owner’s manual is the maximum braked towing limit for the towing vehicle.
What is your kerb weight (KW)?
The kerb weight of your tow vehicle is how much it weighs when it is fully loaded with oil, fluids, and a full tank of fuel but otherwise empty.
This includes accessories fitted after your car was built, including a roof rack, an extra spare wheel, bull bar, or possibly your tow bar.
What is the tare weight of your tow vehicle?
Your vehicle’s tare weight is its empty weight with all fluids filled and 10 litres of fuel.
Like the kerb weight, the car is otherwise empty, and aftermarket accessories are not included.
What is your maximum tow ball weight/load capacity?
Your maximum tow ball weight, also called tow ball download, is the maximum weight your tow vehicle is allowed on its tow ball.
When you connect your caravan to your tow vehicle, weight is transferred from the caravan to your car.This is because caravans are designed to be front heavy to keep them hitched onto your vehicle.
What is your gross combination mass (GCM)?
Your GCM mass refers to the maximum weight of the caravan and car combined, which is decided by the vehicle manufacturer.
Gross combination mass includes absolutely everything loaded into your caravan or car, such as people, accessories, luggage, food, fuel etc.
What is your gross vehicle mass (GVM)?
The vehicle manufacturer sets the GVM. GVM is the maximum allowable weight your tow vehicle can be.
This includes the weight of your car and everything it is carrying; passengers, fuel, luggage, and the tow ball mass from your caravan.
What is the payload of your tow vehicle?
The payload of your tow vehicle is how much weight it can carry in addition to its weight when empty. By subtracting the kerb weight (KM) from the gross vehicle mass (GVM), you get your your maximum payload with your fuel tank full.
Does your tow bar have its own tow capacity?
Your tow bar is not necessarily rated to tow the same weight as your tow vehicle. If your tow bar is rated lower than your car, you must not exceed that limit or vice versa. It is imperitive to have a towbar rated at or above the amount you are weight you are towing
What do the caravan weights mean?
Tow ball weight, gross trailer mass, aggregate trailer mass, and tare mass are some of the key weights that caravan manufacturers
provide for safe towing. Please note how caravan weight is defined as you must understand them for legal and safe towing.
What is your caravans tare weight?
The caravan tare weight is how much the caravan weighs completely empty with only the accessories and options fitted at the time of the build. When the tare weight is measured, all water tanks and gas bottles are empty.
What is your caravans tow ball mass (TBM)
Your caravans tow ball mass is the downward weight of the coupling where it attaches to the tow vehicle. This is sometimes called ball weight or tow ball download.
There should be an empty tow ball weight on the compliance plate. If not, find your aggregate trailer mass (ATM) and subtract the gross trailer mass (GTM), which will give you your empty ball weight.
Keep in mind your tow ball weight will shift depending on if your caravan is loaded with more weight in front of or behind the axle, how full your gas bottles are, and if your water tanks are full or empty. It is a good idea to check with a tow ball scale before you leave on your trip.
What is your caravans aggregate trailer mass (ATM)
Your caravan’s aggregate trailer mass (ATM) is the maximum allowable weight of the caravan and everything inside or fitted to it when separate from your tow vehicle. Included in the ATM is the weight of the caravan, water in the tanks, gas in the gas bottles, food, clothes, modifications, etc.
The ATM is set by caravan manufacturers when the caravan is built.
What is your caravan's gross trailer mass (GTM)?
The maximum allowable weight on the caravan’s axles when connected to a tow vehicle makes up your gross trailer mass (GTM). Since the ball weight of the caravan is being carried by the car, this is different to your aggregate trailer mass (ATM).
If you need to work this out, subtract the empty tow ball weight of the caravan from the ATM.
What is your caravans payload?
Your caravans payload is how much you can load into it. To work this out, simply subtract your caravans tare weight from its aggregate trailer mass (ATM).
Any weight added to your caravan after the build comes out of your payload, including modifications, gas in the bottles, water in the tanks, caravan accessories, etc.
Summary
Understanding these critical weights and what they mean will allow you to safely and legally tow a caravan. Create a list of these weights and take them with you when looking at caravans. Ensure you have the correct information for your vehicle’s specific make, model and variant.Below is a sample list of what the weights of your tow vehicle could look like:
• Gross vehicle mass: 3,350kg
• Kerb weight: 2,635kg
• Maximum payload: 715kg
• Maximum towing capacity: 3,500kg
• Maximum ball weight: 350kg
• Gross combination mass: 6,730kg
In this case, 3,500kg is the maximum towing capacity for this vehicle. This informs what caravans you can tow (and buy at a dealership without changing your Tow vehicle)
In this example, that leaves 3,230kg out of the gross combined mass (GCM). Subtract your vehicle’s kerb weight (KW), leaving 595kg to load your car.
If the caravan you’re towing has a ball weight of 350kg, that will leave 365kg from your car’s gross vehicle mass (GVM) or maximum
payload. Anybody in your vehicle, luggage, modifications etc., also comes out of your maximum payload.
You will need a serious tow vehicle like this to tow a Regent Caravan. Now you are ready to start looking for a suitable caravan.
Discover our range of Discoverer,Cruiser, and Slide-Out Caravans.