Use this glossary to understand common terms used across Boss Aluminium products, vehicle builds, towing, GVM upgrades, trays, canopies and 4WD accessories.
GVM: Gross Vehicle Mass. The maximum legal weight of the vehicle when fully loaded. This includes the vehicle, passengers, fuel, accessories, cargo and any tow ball weight applied by a trailer.
GCM: Gross Combination Mass. The maximum allowable combined weight of the loaded vehicle and loaded trailer when coupled together. GCM is not always the same as simply adding the vehicle's GVM and braked towing capacity together.
BTC: Braked Towing Capacity. The maximum trailer weight a vehicle is rated to tow when the trailer has its own braking system.
ATM: Aggregate Trailer Mass. The maximum loaded weight of a trailer when it is not coupled to the tow vehicle.
GTM: Gross Trailer Mass. The maximum weight applied to the trailer wheels when the trailer is loaded and coupled to the tow vehicle.
TBM: Tow Ball Mass. The downward weight applied to the tow ball by the trailer. This weight is applied to the vehicle and must be considered when calculating payload and GVM.
Payload: The amount of weight a vehicle or trailer can legally carry. Payload generally includes passengers, accessories, cargo, tools, water, fuel and other fitted equipment.
Kerb Weight: The weight of the vehicle in standard form with fluids and fuel, but without passengers, accessories or cargo.
Tare Weight: The weight of an empty vehicle or trailer. The exact definition can vary depending on the manufacturer or registration details.
Axle Load: The amount of weight applied to a vehicle's front or rear axle. Each axle has a maximum allowable load rating.
GVM Upgrade: A certified upgrade that increases the vehicle's Gross Vehicle Mass, allowing the vehicle to legally carry more weight when approved and fitted correctly.
Pre Rego: A vehicle that is brand new and has not yet been registered. Some modifications and GVM upgrades may be completed and certified before first registration.
Post Rego: A vehicle that has already been registered. Some upgrades and modifications may require different approval or certification processes once a vehicle is registered.
ADR: Australian Design Rules. National standards for vehicle safety, anti theft and emissions requirements.
Tray: A rear vehicle body with an open load area, usually fitted to a ute or cab chassis vehicle.
Canopy: An enclosed rear storage body fitted to a tray, tub or chassis. Canopies are commonly used for touring, trade, fleet and recreational vehicle builds.
Service Body: A rear body designed for trade, fleet, commercial or field service use, often with organised storage, tool access and equipment mounting.
Powder Coating: A durable coating process where powder is applied to metal and baked to form a protective finish.
Marine Grade Aluminium: Aluminium selected for strength, corrosion resistance and durability, commonly used in harsh outdoor, coastal and off road environments.
Pre Treatment: The surface preparation process completed before powder coating to improve coating adhesion and long term corrosion resistance.
Towbar Rating: The maximum weight a towbar is rated to tow. The vehicle, towbar and trailer ratings must all be considered, and the lowest applicable rating must be followed.
This glossary is provided as a general guide only. Always refer to your vehicle manufacturer, compliance plate, engineer, certifier or relevant road authority for vehicle specific requirements.
