A similar class of vehicle is the CUV crossover, a common UK term. That is built on a car chassis. Often it uses a Unibody chassis instead of the heavier body-on-frame design of SUVs. Crossover vehicles often have all-wheel-drive instead of four-wheel drive. Crossovers are usually lighter than SUVs and get better fuel mileage. In general, when referring to an SUV, many include crossovers. However it is incorrect to refer to an SUV on a truck frame as a crossover.