A motorcycle (also called a motorbicycle, motorbike, bike, or cycle) is a single-track, two-wheeled motor vehicle powered by an engine. Motorcycles vary considerably depending on the task for which they are designed, such as long distance travel, navigating congested urban traffic, cruising, sport and racing, or off-road conditions. In many parts of the world, motorcycles are among the least expensive and most widespread forms of motorised transport. Traditionally, motorcycles used a lot less fuel than cars but modern engines and aerodynamics have largely eliminated this advantage for familiar western motorcycles used for leisure and touring.