Curb Weight
Curb weight is the mass of a vehicle in a defined ready-to-operate condition, without occupants or cargo. The exact inclusions depend on the regulation or manufacturer: standard equipment and operating fluids are normally included, while a driver, luggage, optional equipment, or a nominal fuel quantity may be treated differently.
Why the definition matters
An EV's traction battery is part of the vehicle and is included in curb weight. A large battery can therefore raise curb weight even when the cabin and luggage space are unchanged. Curb weight is not the same as the vehicle's current scale weight, and it is not automatically identical to European “mass in running order.”
Curb weight is often used when estimating payload by subtracting it from the applicable maximum rated mass. That comparison is valid only when both figures describe the same variant, equipment configuration, and measurement system. Options such as larger wheels, powered seats, or a tow hitch can increase the actual vehicle mass and reduce the load margin.
For the wider relationship between vehicle mass, dimensions, and rated limits, see Vehicle Dimensions and Mass.