How much can your vehicle legally tow- a -boat?
is is crucial to the safety to you and your family and other families on the road.
How many of us have ever had:
- Our vehicle weighed fully loaded.
- Our boat, caravan or camper weighed fully loaded.
Then, working out what weight you are allowed to carry and tow legally can be very confusing.
The easiest way to be sure of these important weights when travelling is to use your nearest public weighbridge. Having your vehicle weighed fully loaded and your caravan, boat, camper or camper trailer with everything in them it becomes at a very reasonable cost for peace of mind when on the road.
Tare Weight – Vehicle from Factory
The Tare weight is an empty standard vehicle with all its fluids (oils, coolants) but with only 10 litres of fuel in the tank.
The Tare Mass Weight or Kerb Mass
The Kerb Mass is a standard vehicle with all its fluids, a full tank of fuel and driver, but without any accessories fitted to the vehicle (bull bars, tow bars, roof racks, trays on cab chassis Etc). Think of your standard vehicle literally parked at the kerb.
Gross Vehicle Mass (GVM)
This is the maximum your vehicle can weight when fully loaded and accessorised. This weight as specified by the manufacturer of the vehicle. You will usually find this GVM figure on the vehicle’s Vin Plate or in the owner’s manual. The GVM is equal to Tare Mass Weight or Kerb Mass plus all passengers, accessories and fully loaded.
Payload – (This is where it becomes interesting)
The payload is the maximum load your vehicle can carry as specified by the manufacturer. By deducting your vehicle’s Kerb Mass from its Gross Vehicle Mass (GVM) lets you know what load you can carry in your vehicle. Things such as Luggage, Camping Gear, Food & Water, Eskies, Roof Top Tents, Tools, Extra Passengers Etc., can seriously bite into your payload.
In example we have a vehicle with a kerb Mass of 2190kg as rolled out of the factory, with a few accessories showing how it can add up quickly to the GVM.
Example: (Vehicle Manufacturer gives you a GVM of 3400kg – Vehicle kerb weight of 2190kg leaving you with a payload of 1210kg) ( 3400kg – 2190kg = 1210kg)
But as shown in the example, you have used up * 315kg so now you are left with 895 kg for other things like clothes, food, drinks, eskies, Roof Top Tent and other passengers ETC. Not including towing and all other things not added to the list above.
Example
| Vehicle – Kerb Weight | 2190kg |
| Add Accessories below: | |
| Tow Bar | 60kg |
| Bull Bar & Winch | 100kg |
| Extra Spare Wheel | 15kg |
| Roof Rack | 40kg |
| Dual Tool Boxes | 300kg |
| Your Passenger | 100kg |
| Total Accessories adds up to | 315kg |
| The GMV Total now is | 2805kg |
–Tow Ball Download
One thing to remember if towing you will need to include the Tow Ball Download that must be added to the GVM of the vehicle.
The Tow Ball Download or TBD is something we, most of the time forget. As a rule, the Tow-Ball Download is usually around 10% of the Gross Trailer Mass. The Tow Ball Download is also referred to as downward force/weight, the maximum vertical weight that can be applied on the tow ball without taking too much weight off the front wheels and reducing the vehicle’s ability to steer and brake. This is one reason why front-wheel-drive vehicles have a lower towing capacity than four – wheel-drive vehicles.
It is a vital safety procedure to ensure your tow ball weight is correct for towing. An incorrect tow ball weight can lead to an increased chance of accidents, increase your fuel consumption and it may also void your vehicle insurance. If your tow ball weight is too heavy or too light it may contribute to a range of dangerous situations including sway, loss of traction, loss of steering control and difficulty braking safely. The Milenco tow ball weight scale is a simple, inexpensive and easy way to ensure you have the correct tow-ball download weight, every-time you take off on a trip, weight distribution is most important. It will amaze you, how packing your caravan, camper-van or boat makes a big difference. Suitable for caravans, pop tops, boats, camper trailers and horse floats. A very small price to pay for safety.
Now when towing a Box Trailer, Caravan, Boat, Horse-float, Single, Dual or Tri. Axle Trailers is another story.
Un-braked towing capacity: This figure refers to towing a trailer without brakes and is usually significantly lower than the braked towing capacity because, the vehicle must absorb all of the braking force.
Braked Towing Capacity: This is the most common and refers to the ATM of a trailer which has its own brakes on the trailer, caravan, camper, Horse-float Etc and is connected to the car with a brake controller.
Tare Trailer Mass (TARE)
The Tare is the weight of an empty trailer. The term ‘trailer’ covers everything you can tow or ‘trail’ behind a vehicle, from a single-axle box trailer, camper trailer, motorcycle trailer, jet-ski trailer & boat trailer right on up to heavy duty dual or tri axle trailers and including caravans. If it’s a camper trailer or caravan, its Tare Mass does not include fluids in Water Tanks, LPG tanks, Toilet Waste. Clothes, Food, Bar-b-que’s, Eskies, Etc. As this is known as Dry Weight for obvious reasons.
Aggregate Trailer Mass (ATM)
The ATM is the maximum towing weight of the trailer/caravan as specified by the manufacturer. This is the maximum axle load that your trailer is designed to carry as specified by its manufacturer. It is the combined weight of your trailer and its payload.
Gross Combination Mass (GCM)
The Gross Combined Mass is the maximum weight allowed for your vehicle and trailer combined, as specified by the tow vehicle’s manufacturer. This is where you must pay close attention to your vehicle’s GVM and your trailer’s ATM, because those two figures determined make up the Gross Combination Mass Weight or GCM and one directly affects the other.
Example: Your vehicle has a GVM of 3500kg and a towable ATM of 3500kg leaving you with a GCM Gross Combination Mass of 7000 kg.
When purchasing a caravan, a boat or a tow-vehicle or both, the weight rating vin plates can all get a little confusing to know what you’re legally allowed to tow or even how to calculate towing capacity. But it is essential to understand that your setup doesn’t exceed Gross Combination Mass as it could void your insurance if things go wrong. If you’re armed with the correct knowledge, in the long run it could save you money and time over & over again. The simple equation to remember is * Gross Trailer Mass + Gross Vehicle Mass = The Gross Combination Mass
Say you are looking at a vehicle that says it can tow up to 3,500kg and whilst the manufacturer tells you that technically, yes, you can tow up to 3,500kg, but you may need to compromise on your payload to do so. Big time! The other thing you must check on, is that your vehicle’s towing capacity is only as good as the towbar rating. The towbar’s maximum towing weight may be different to the one set for the vehicle.
Example: If your vehicle has a towing capacity of 2800kg but the towbar is rated at 2500kg you will only be allowed to tow up to 2500kg. Alternatively, if the towbar is rated at 3000kg and car’s towing capacity is 2800kg that is fine, something to check on. Another thing to check on is the size coupling and the tow ball as they have different rating as well – 70mm balls can tow more than a 50mm ball.
Here are just a couple of examples on different vehicles.
Example One: The New 79 Series Landcruiser Dual Cab GXL Ute has a – Tare Mass Weight or Kerb weight of 2175kg. The GVM weight must include a tray & bull bar, winch, dual under tray toolboxes each side, spotlights, tow bar, full tank of fuel, yourself and any other goodies you are wanting to add. The Vehicle Manufacturer specify the GVM is to be no more than 3300kg. Leaving you with a payload of 1125kg. Your accessories fitted to the vehicle, passengers, plus your load will quickly take up the 1125kg payload load capacity. The other thing to remember if towing, add in your Tow Ball Download Weight to the payload as well. The Gross Vehicle Mass is 3300kg & the Braked Towing Capacity is 3500kg so Gross Combined Weight is 6800kg less your GVM of 3300kg leaving you a tow weight of 3500kg.
Example Two: The New 1500 RAM Laramie V6 Eco-diesel vehicle has a Tare Mass Weight of 2715kg or Kerb Weight. The GVM weight is 3450kg this is to include bull bar, spotlights, light bar, full tank of fuel and yourself – Leaving you with a payload of 735Kg. Add the weight of the passengers, plus the tow ball download of the item being towed restricts what you are allowed to carry when towing. The Maximum braked towing is *3500kg with 50mm ball. The Gross Combined Mass Weight is 6692kg less your GVM of 3450kg leaving you a tow weight of 3242kg.
*Maximum braked towing capacity of 3500kg is subject to regulatory requirements and vehicle weight restrictions (which may require occupants and/or luggage to be restricted).
#All information as per the Ram Technical Specification Brochure.
Upgrade to: The New 1500 RAM Laramie 5.7ltr V8 Petrol it has a Tare Mass Weight of 2650kg or Kerb Weight. The GVM weight is 3450kg this is to include bull bar, spotlights, light bar, full tank of fuel and yourself – Leaving you with a payload of 800kg. Add the weight of the passengers, plus the tow ball download of the item being towed restricts what you are allowed to carry when towing. The Maximum braked towing is *4500kg with 70mm ball. The Gross Combined Mass Weight is 7237kg less your GVM of 3450kg leaving you a tow weight of 3787kg.
* Maximum braked towing capacity of 4500kg is subject to regulatory requirements and vehicle weight restrictions (which may require occupants and/or luggage to be restricted)
# All information as per the Ram Technical Specification Brochure.
Example Three- The New 2500 RAM Laramie Crew Cab Petrol vehicle has a Tare Mass Weight of 3577kg or Kerb Weight. The GVM weight is 4490kg this is to include bull bar, spotlights, light bar, full tank of fuel and yourself – Leaving you with a payload of 913kg. Add the weight of the passengers, plus the tow ball download of the item being towed restricts what you are allowed to carry when towing. The Maximum braked towing is 3500kg using a 50mm The Gross Combined Mass Weight is 7990kg for 3.5t towing less your GVM of 4490kg leaving you a tow weight of 3500kg. The Max braked towing is 3500kg with a 50mm ball – 4500kg with 70mm ball and 6942kg using a pintel, this shows how tow ball can change the Maximum Braked towing weight.
50mm Ball – Take the Gross Combined Weight is 7990kg less your GVM of 4490kg leaves you with a tow weight of * 3500kg
70mm Ball – Take the Gross Combined Weight is 8990kg less your GVM of 4490kg leaves you with a tow weight of * 4500kg
Pintel – Take the Gross Combined Weight is √ 11,432kg less your GVM of 4490kg leaves you with a tow weight of * 6942kg
* Maximum braked towing capacities are subject to regulatory requirements and vehicle weight restrictions (which may require occupants and/or luggage to be restricted)
+ There is limited stock and the new 2500, new model due around Nov 2020
√ Compliance to State and Territory towing regulations
# All information above as per the Ram Technical Specification Brochure
If this all seems a bit confusing, it is, which is why it is best to go to your local weighbridge to see if you are safe to tow. There is a solution to this, if you have a problem with tow capacity and payload.
Many vehicles are not manufactured to carry the payload of the wonderful campers on the market on the back of our vehicles today. So many of us have had to look at upgrading our vehicles to accommodate our payload without comprising on our tow weight. You can get Upgrade Kits for a wide range of vehicles that are certified by the Department of Infrastructure and Transport, these come with warranty. This is the ideal choice for when towing caravans, horse floats, camper and general trailers who need that extra load carrying capacity.
When a GVM Upgrade kit has been installed to a new vehicle, a new compliance plate must be fitted to comply with the new GVM. Then the new vehicle can now be registered with the new increased G.V.M. This procedure will allow the vehicle to be legally used in all states of Australia.
For vehicles that have already been road registered, the vehicle is to be inspected by an authorised Automotive Engineer in that state and be issued with a new compliance.
Recently we have noticed an assortment of six wheel conversions on all different types of vehicles, coming into our marine business, we decided to do some homework as we have a weight problem with our camper on the back of our current 78 Series Toyota 2006 Ute.
We found the Toyota Land Cruiser 79 is a popular vehicle for these conversions. Other options are the Ford Ranger, Toyota Hilux, Mazda BT-50, Isuzu D-Max. Most of these pickups are converted for work purposes because many have problems with the payload and the tow capacity. In Australian car license covers vehicles up to 4500kg, so many people started to look for more payload and longer trays on their utes for storage and their campers.
The best thing about the Toyota 79 Series Dual Cab 6-wheeler Ute it’s modified for the same track width as a front-end tracking, some trails/tracks are too narrow for wide trucks like the US trucks. The Toyota 6×6 conversions give them a larger pickup truck vehicle, without the need to buy expensive spare parts. The tandem axle is, when properly implemented a lot more comfortable on rough tracks.
Example: The New 79 Series Landcruiser Dual Cab GXL Ute – Six-Wheeler has a – Tare Mass Weight or Kerb weight of 2500kg. The GVM weight must include all the bolt on accessories like a tray & bull bar, winch, dual under tray toolboxes each side, spotlights, tow bar, full tank of fuel, yourself and any other goodies you are wanting to add. With the upgrade GVM will be 4495kg. Leaving you with a payload of 1995kg. The other thing to remember if towing, take out your Tow Ball Download Weight as well. The Braked Towing capacity is 4500kg leaving the Gross Combined Weight is 8950kg less your GVM of 4405kg leaving you a tow weight of 4500kg.) Making a big difference to the payload capacity. The Six-Wheeler Conversion Company like to look at each customers circumstance and requirements to arrive at the best result for them, within the appropriate regulations.
Many of the used vehicles can have their suspension up graded with new coils, springs, 4×4 gas shocks & U-bolts plus fitting. Many businesses out there have the expertise to upgrade your existing vehicle and your GVM plate as well.
So, if you are planning to purchase a new vehicle or have realised that your current vehicle isn’t quite handling the load, there is a solution. Some upgrades must be done from new but there are other upgrades that can done to your existing vehicle to improve your payload. I do hope we have made this a little easier to understand and you have gained more knowledge on this subject and may be of some benefit to you all.