A truck (US, CA and AU) or lorry (UK and Ireland) is a motor vehicle designed to transport cargo. Trucks vary greatly in size, power, and configuration, with the smallest being mechanically similar to an automobile. Commercial trucks can be very large and powerful, and may be configured to mount specialized equipment, such as in the case of fire trucks and concrete mixers and suction excavators. Modern trucks are largely powered by diesel engines exclusively, although small to medium size trucks with gasoline engines exist in America. In the European Union vehicles with a gross combination mass of less than 3,500 kilograms (7,716 lb) are known as light commercial vehicles and those over as large goods vehicles.