Your suspension in your RV is as important as the suspension setup in your tow vehicle.
Suspension, weight awareness and weight distribution are often overlooked but it can be critical to keeping you safe and supported out on the road.
At RVGO we can assess your current set up using our weighing systems and advise you on the best setup to suit your personal requirements for road or off-road usage.
Tare Mass? GVM? Kerb Mass? GCM? It all gets a little confusing, below is an overview to help you to understand the weight capacity of your vehicle and trailer.
With this knowledge it will allow for educated decisions next time you load up the car or rv to ensure a safer and legal trip.
Tare Mass, GVM, Kerb Mass & GCM will be found on your vehicles compliance plate and in the owner’s manual. These terms refer to how much your vehicles is designed to carry or tow.
Tare Mass or Weight
This is the weight of an empty vehicle with all fluids but only allowing for 10 litres of fuel.
Kerb Mass or Weight
This is the same as Tare Mass, but includes a full tank of fuel but doesn’t account for any accessories such as bull bars, towbars, roof racks etc. Basically your standard vehicle parked at the kerb, ready for you to get in and drive away.
Gross Vehicle Mass (GVM) or Weight (GVW)
This is the maximum your vehicle can weigh when fully loaded as outlined by the manufacturer. You will usually find the GVM figure on the vehicle's weight placard (generally in the driver's door opening) or in the owner's manual. So GVM is the Kerb Mass plus all accessories bull bars, roof racks etc and includes Payload and Tow Ball Download.
This is the maximum load your vehicle can carry as outlined by the manufacturer. Deduct your vehicle's Kerb Mass from its Gross Vehicle Mass (GVM) and what's left is the amount of things / people you can load into it including luggage. For example, if your vehicle has a 1000 kg (1.0 tonne) payload, five big adults will use up about half of that before you even start packing in luggage, a picnic basket and a few bevies.
Tow Bar Download (TBD)
Very important, the amount of weight on your tow bar is crucial to safe towing. Your towbar will have a placard showing the maximum tow bar capacity and maximum tow bar download. Make sure the tow bar you choose is designed to suit your vehicle and your towing capacity requirements. The TBD should also be around 10-15 % of the Gross Trailer Mass (GTM), which for peace of mind can also be calculated using the GTM and TBD figures as shown here: TBD divided by GTM x 100 = % of GTM
As an example, if your vehicle has a Kerb Mass of 2500 kg, a GVM of 3500 kg and a GCM of 5000 kg. At its Kerb Mass of 2500 kg the manufacturer says it can legally tow another 2500 kg, but that towing weight decreases in direct proportion to how much the tow vehicle's weight increases. So if you load up the towing vehicle to its GVM of 3500 kg (or a payload of 1000 kg), that would only leave a towing capacity of 1500 kg to meet the GCM of 5000 kg. If the tow vehicle's GVM dropped to 3000 kg (or a payload of 500 kg), its towing capacity would increase to 2000 kg and so on. We strongly recommend pulling out your vehicle manual to check your figures.