Automotive Terms - H

Handling

It is the ease with which the vehicle is steered and manoeuvred around turns, up hills, etc.

Hatchback

A car with no extended boot and has a full height tail gate that includes a rear window.

Head Room

It is the distance between the top of a passenger’s head and the roof of the vehicle.

Horsepower (hp, bhp)

Abbreviated as hp, as in 200-hp engine, or bhp (brake horsepower or net horsepower) to designate power produced by an engine. In general, the higher the horsepower, the higher the vehicle's top speed. One horsepower is the power needed to lift a 550-pound weight one foot in one second.

Automotive Terms - I

In-Line Engine

Cylinders are arranged side by side in a row and in a single bank. Most four-cylinder and some six-cylinder engines are in-line engines. In V-6, V-8 or V-12 engines, the cylinders are divided into two banks, each of which is angled away from the other in a 'V.'

Independent Suspension

A suspension design that lets each wheel move up and down independently of the others. A vehicle can have two-wheel or four-wheel independent suspension; sportier models have four-wheel independent suspension. See also Multi-Link Suspension, Live Axle.

Instrument Panel

The instrument panel contains the gauges in front of the driver; the controls for the sound system and climate-control system; the glove box; vents for the windshield defroster; and the front passenger-side airbag. The instrument panel is often delivered to the factory as a complete module with electronic components already installed.

Integrated Child Seats

May also be called integrated child-safety seats or integrated child-restraint seats. Built-in child seats that fold out of the seatback of a rear seat. Sedans with this option usually have one in the center of the rear seat; minivans may have one or two in the middle seating positions. While NHTSA and every other safety organization stress that any child-restraint seat is better than none, built-in child-restraint seats are considered the safest alternative because they are more securely anchored than a seat attached to seat belts.

Intercooler

Device that cools air as it leaves a turbocharger or supercharger before the air is blown into the engine air intake. Cooling makes the air denser and richer in oxygen, which lets the engine produce more power.

Automotive Terms - J

Jack


A jack is a mechanical device used to lift heavy loads or apply great forces. Jacks employ a screw thread or hydraulic cylinder to apply very high linear forces.

Automotive Terms - K

Keyless Entry

A system for locking and unlocking doors of a vehicle with a central locking system without using the key. Usually, the user controls the locks by pressing a button on a remote key-fob transmitter. Some vehicles have electronic combination locks on the doors near the handle.

Automotive Terms - L

Leaf Spring

Suspension spring made up of several thin, curved, hardened-steel or composite-material plates attached at the ends to the vehicle underbody. The curved shape of the plates allows them to flex and absorb bumps.

Leg Room

With the front seat adjusted all the way back, the distance from the accelerator pedal's heel point to the back of the front seat cushion.

Automotive Terms - M

MacPherson Strut

A MacPherson strut is a unit that includes a damper or shock absorber cartridge inside a large, long metal spring. MacPherson struts are used over the front wheels of most front-drive cars. Replacement of MacPherson strut cartridges requires a spring compressor.

Make

The manufacturer of the vehicle (BMW, Chrysler, Honda).

Manual Transmission

A transmission that varies the power and torque through a foot pedal controlled clutch and a floor-mounted or steering-shaft-mounted gear selection lever.

Minimum Ground Clearance

The distance between the ground and the lowest point of the vehicle chassis (usually the axle). A vehicle can drive over any object shorter than its minimum ground clearance.

Moonroof

A window-type opening in the roof of the car that can open or tilt up or down. See Sunroof.

Muffler

The exhaust system device in the tailpipe that reduces engine noise. Some vehicles have more than one muffler along the tailpipe.

Multi-Link Suspension

Independent suspension controlled with several link arms that restrict undesired motion of the suspension for a smoother ride and more precise handling.

Multi-Port Fuel Injection

An electronic fuel-injection method that uses individual injectors to spray fuel directly into each intake port, bypassing the intake manifold. Also called multi-point fuel injection.

Automotive Terms - O

Overdrive

A transmission gear with a ratio below 1:1, which improves fuel economy by reducing engine revolutions per minute at highway speeds. On a five-speed manual transmission, the fourth and fifth gears are overdrive. On a four-speed automatic transmission, the fourth gear is overdrive. When an overdrive gear set is engaged, the output shaft turns at a higher rate than the input shaft, reducing engine revolutions at cruising or highway speeds.

Overhead Cam (OHC)

The camshaft is on top of the cylinder head on overhead-cam engines. Single overhead-cam (SOHC) engines have a single cam above the cylinder head. Dual overhead-cam (DOHC) engines have two cams above the cylinder head. All overhead-cam engines are also overhead-valve (OHV) engines, which means the intake and exhaust valves sit atop the cylinder head.

Oversteer

Occurs when the rear tires lose adhesion under cornering. In motorsports, this is also called loose. Oversteer can lead to a spin if the driver doesn't reduce acceleration. See also Understeer.