An engine can be located at the
An engine located at the front can be mounted longitudinally, and can drive either the front, or the rear wheels. In 4-wheel-drive applications, it can drive both the front and rear wheels.
Alternatively, the engine can be transverse, and drive either the front wheels only, or, in 4-wheel-drive applications, the front and rear wheels.
Mid-engined vehicles have the engine in front of the rear wheels. The engine can be transverse or longitudinal, and usually drives the rear wheels only.
Rear-engined vehicles have the engine mounted behind the rear wheels. The engine can be transverse or longitudinal, and usually drives the rear wheels only.
The drive train transfers turning effort from the engine to the driving wheels.
A drive train can include a clutch for manual transmission, or a torque converter for automatic transmission; a transmission, a drive shaft, final drive and differential gears, and driving axles.
Alternatively, a transaxle may be used. A transaxle is a self-contained unit, with the transmission, final drive gears and differential located in one casing.
It is usually used on front-engined, front-wheel-drive vehicles, or, rear-engined, rear-wheel-drive vehicles.
It can also be used on front-engine, rear-wheel-drive vehicles, connected to the engine by a propeller shaft.