Kerb weight is the weight of a car ready to drive but with no occupants or luggage — including all fluids, standard equipment and (by convention in India) a fuel tank at or near full. It is the baseline figure for judging a car's fuel efficiency, performance and agility, since every extra kilogram must be accelerated, braked and steered.
Kerb weight vs gross vehicle weight
Kerb weight is the empty-but-ready figure; Gross Vehicle Weight (GVW) is the maximum the car may legally weigh fully loaded, as certified by the manufacturer. The difference between the two is the payload — how much weight in people and luggage the car can carry. A car with a 1,200 kg kerb weight and 1,650 kg GVW can carry 450 kg: roughly five adults and their bags. Definitions of "kerb" vary slightly between manufacturers (some quote with 90% fuel, some without driver), so treat small differences between brochures as noise.
Why it matters when buying
Divide engine power by kerb weight to get the power-to-weight ratio — the single best spec-sheet predictor of how quick a car feels. Weight also drives fuel economy: heavier cars work the engine harder, which is why a 700 kg Alto K10 can post 24+ km/l ARAI while a 2,000 kg-plus Fortuner manages around 10. Lighter is not automatically worse for safety, either — crash protection comes from structural design, not mass alone, though in a two-car collision the heavier vehicle does hold a physics advantage. Compare kerb weights when two rivals share an engine: the lighter one will usually be both quicker and more frugal.