Vehicle weight is a measurement of wheeled motor vehicles; either an actual measured weight of the vehicle under defined conditions or a gross weight rating for its weight carrying capacity.
Curb weight (American English) or kerb weight (British English) is the total mass of a vehicle with standard equipment and all necessary operating consumables such as motor oil, transmission oil, brake fluid, coolant, air conditioning refrigerant, and sometimes a full tank of fuel, while not loaded with either passengers or cargo. The gross vehicle weight is larger and includes the maximum payload of passengers and cargo.
This definition may differ from definitions used by governmental regulatory agencies or other organizations. For example, many European Union manufacturers include the weight of a 75-kilogram (165 lb) driver and luggage to follow European Directive 95/48/EC. Organizations may also define curb weight with fixed levels of fuel and other variables to equalize the value for the comparison of different vehicles.
The United States Environmental Protection Agency regulations define curb weight as follows: Curb weight means the actual or the manufacturer’s estimated weight of the vehicle in operational status with all standard equipment, and weight of fuel at nominal tank capacity, and the weight of optional equipment computed in accordance with §86.1832–01; incomplete light-duty trucks shall have the curb weight specified by the manufacturer.
For a motorcycle, wet weight is the equivalent term.
Dry weight is the weight of a vehicle without any consumables, passengers, or cargo. It is significantly less than the weight of a vehicle in a driveable condition and therefore rarely used. Quoting a dry weight can make a car’s weight and power-to-weight figures appear far more favorable than those of rival cars using curb weight.
The difference between dry weight and curb weight depends on many variables such as the capacity of the fuel tank. There is no standard for dry weight, so it’s open to interpretations.
Some vehicle manufacturers have used the term shipping weight, which refers to the vehicle in as-built, no-option condition. This would include engine oil, coolant, brake fluid and at least some small quantity of fuel, as vehicles have traditionally been driven off the assembly line and these fluids were necessary to do so.