'Truck' is the most common name applied to larger commercial vehicles in The US and Australia. A goods carrying vehicle in the UK is more likely to be called a 'lorry', or a 'heavy goods vehicle', or HGV. Lighter types of commercial vehicles are known by a variety of names that differ from place to place. For instance, a light commercial vehicle that may have a front cab configuration similar in size to a family sedan or an SUV but with an open top cargo area at the rear is known in the US as a 'pick-up', but in Australia and New Zealand it is called a 'ute' or utility vehicle.
Most heavier trucks share a common construction: they comprise a chassis with a cab; axles, suspension and wheels; and an engine and a drivetrain. The body or coachwork is usually customized for the particular goods that it will carry – for instance, sealed tanks for liquids such as fuels; open trays for bulky general goods such as timber; or enclosed and refrigerated containers for perishable goods such as meat.
A truck chassis usually consists of parallel steel beams held together with cross members. This forms the framework to which all the other components are attached.
The cab is the enclosed space where the driver sits. In larger long-haul vehicles, this will be a comfortable air-conditioned space that can even contain a sleeping compartment. A conventional truck cab is behind the engine which sits under a front hood or bonnet, as it would be in a passenger vehicle. In Europe, where truck lengths are more strictly regulated, it is much more common for the driver to sit on top of the engine and front axle in a cab which tilts forward to allow access to technicians. Light trucks such as pickup trucks can have a unibody cab like a passenger vehicle, attached to a half-chassis behind.
There are fewer truck engine manufacturers than there are for passenger vehicles, and many trucks in the US and Australia are built using engines from a third party manufacturer such as Cummins, Navistar, or Caterpillar. Fully integrated trucks from a manufacturers such as Scania, MAN, Mercedes, or Volvo, are more common in Europe.
Light trucks can use gasoline/petrol engines, but heavier trucks are mostly powered by four-stroke diesel engines with turbochargers and intercoolers, although there are alternatives such as the V12 diesel two-stroke engine from Detroit Diesel.
Larger trucks usually have manual transmissions with several ranges and many more gears than passenger vehicles. To cope with the torque forces required to start heavy loads moving, truck transmissions are more strongly built than passenger vehicle transmissions. Automatic transmissions are becoming more common in all types of trucks.
Truck types and examples
Light trucks – pickups, minivans
Medium trucks – delivery vehicles, motor homes
Heavy trucks – concrete mixers, gasoline/petrol tankers, garbage trucks
Articulated trucks, or semi-trailers – car transporters, containers
Doubles and 'Road Trains' – trucks with multiple trailers for carrying livestock, grain, ore