FRONT ENGINE: Describes a vehicle whose engine is located at the front of a vehicle above the front suspension.

FLAT EIGHT: Describes an eight-cylinder engine with four cylinders on each side. The "left" bank of four cylinders is directly opposite the right bank.

FLAT FOUR: Describes a four-cylinder engine with two cylinders on each side. The "left" bank of two cylinders is directly opposite the right bank.

FLAT SIX: Describes a six-cylinder engine with three cylinders on each side where the "left" bank of three cylinders is directly opposite the right bank.

FLAT TWIN: Describes a two-cylinder engine with one cylinder on each side. The "left" cylinder is directly opposite the "right" cylinder.

FOUR-CYLINDER ENGINE: Describes an engine with four cylinders usually in line, although it can also be V-type or horizontally opposed, commonly found in compact cars.

FOUR VALVE: Describes an engine fitted with four valves (two intakes and two exhaust) for each cylinder.

I HEAD ENGINE: Describes a type of engine whose exhaust and intake valves are situated directly over the piston, while the cam is found in the block with the valves activated by pushrods and rocker arms. More commonly known as an "overhead-valve engine".

GOVERNOR: Describes the device designed to automatically control a car's speed by preventing its engine from exceeding its maximum RPMs.

HORIZONTALLY OPPOSED ENGINE: Describes a car engine fitted with two banks of cylinders placed either flat or 180 degrees apart, thus providing a lower centre of gravity with improved handling and aerodynamics.

HORSEPOWER (HP): Describes the performance levels of a car engine gauged by the equation that one unit of horsepower is equivalent to the ability to lift 33,000 pounds at the rate of one foot in one minute.

HYBRID CAR: Describes a vehicle with a hybrid propulsion system.

HYBRID PROPULSION: Describes a vehicle with two distinct but interdependent propulsion forms that can operate separately or in conjunction. The most common is an electric motor and an internal combustion engine.

IDLE: Denotes the engine speed when the vehicle is not moving.

IDLING: Describes the action of an engine when turning over at low speed on minimum throttle.

IN-LINE ENGINE: Describes an engine in which all the cylinders are arranged in a straight row, either vertically or slanted. The pistons drive a common crankshaft.

IDLE SPEED STABILISER: Describes the device, which ensures a consistent rpm rate for an engine at idle speed.

L-HEAD ENGINE: Describes an internal combustion engine fitted with twin valves in the block and on the same side of the cylinder to form an "L" shape. Used in the early years of automotive engineering, the L shape or side-valve engine is rarely found in modern engines.

LONG BLOCK ENGINE: Describes an engine with a relatively long crankshaft comprising a standard short block engine plus the oil pump and sump, cylinder head, camshaft and the complete valve train. Typically, the term long block engine relates to a 6-cylinder in-line engine with a more extended block than a 4-cylinder or V-8 engine.

LONGITUDINAL ENGINE: Describes a traditional engine layout used on most RWD vehicles where the cylinders are placed lengthways from the front to the back.