Automotive Terms Dictionary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A-arm:
A suspension linkage formed in the shape of an "A" or "V" found commonly on the front suspension. The sides of the two legs of the A-arm are connected to the chassis by rubber bushings and the peak of the A-arm is attached to the wheel assembly. In this way, the wheel can freely move up and down. Sometimes there is an upper A-arm, a lower A-arm, or both upper and lower A-arms. The British call it a "wishbone."

Abacus:
1. The uppermost part of a column capital or pilaster, on which the architrave rests.
2. A bead frame. Used as an arithmetic calculating aid.

Abampere:
A unit of electric current in the CGS electromagnetic system of units. One abampere equals 10A.

Aabamurus:
A supporting wall or buttress, built to add strength to another wall.

Aabandonment:
A voluntary surrender of legal rights or title to a mining claim.

Aabatjour:
An opening to admit light and generally to deflect it downwards; a skylight

Aabaxial:
Rays of light which do not coincide with the optical axis of a lens system.

Aabbe refractometer:
An instrument for measuring directly the refractive index of liquids, minerals, and gemstones.

Accelerator
Gas pedal or throttle. A foot-operated pedal or hand-operated lever connected by linkage or a cable to the throttle plate in the carburetor.

Actual Cash Value (ACV)
The amount of money you spent on the purchase and repairs of a used vehicle.

Afterboil
The boiling of engine coolant after the engine is stopped.

Aftermarket (Replacement Market)
all products and services used in the repair and maintenance of vehicles that was not produced by the original car manufacturer.

Afterruning
(Also called run-on and dieseling) When engine continues to operate after the ignition switch is turned off, can be destructive to an engine

Agent or broker
an intermediary with legal authority to operate on behalf of the manufacturer.

A.I.R
Air Injection Reactor

Air Bag (Supplemental Inflatable Restraint System)
A safety device that flates to provide a cushion of air contained in a bag to absorb impact forces during collisions. Designed to lessen contact with the steering wheel and windshield.

Air Gap
Space between the spark plug electrodes, also known as gap, often adjusted to gain maximum performance.

Air Injection
A system that injects air into the exhaust ports of the engine for combustion of unburned hydrocarbons in the exhaust gases, thus producing "cleaner" exhaust emissions.

A-Pillar
In the side view, the foremost roof support of a vehicle, located in most instances between the outer edge of the windshield and the leading edge of the front door upper. Also known as an A-Post.

Alloy
Mixture of two or more metals

Alloy Wheels
A generic term used to describe any non-steel road wheel. The most common alloy wheels are cast aluminum. Technically, an alloy is a mixture of two or more metals. These wheels are known for their light weight and strength.

Alternating Current (AC)
Flow of electricity that periodically reverses direction

All-Wheel Drive
Sometimes confused with Four wheel drive, it is full time, always on, automatically splits engines torque between all 4 wheels depending on road conditions. Driver does not need to turn this feature on or off as it is always on.

Ampere
After Andre-Marie Ampere, French (1775-1836). The ampere is a unit of electrical current, or the flow of electricity.

Anti-Lock Brake System (ABS)
Automatic control of your braking in case you brake too hard causing your wheels to lock, system automatically releases the break for a split second giving you more control over steering.

Antifreeze
An additive that lowers the freezing point of a liquid

A.T.D.C
After top dead center

Axle Ratio
The ratio between the rotational speed (RPM) of the drive shaft and that of the driven wheel. Gear reduction in final drive is determined by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear.