Helps to clarify some car terms and acronyms. We’ll keep adding to this in alphabetical order.
ABS – Anti-Lock Braking System. See Anti-Skid Braking.
A/C. – Air Conditioning.
Active Rear Wheel Steering – see Passive Rear-Wheel Steering.
Active Suspension – A suspension system that detects changes in the road surface and alters the suspension geometry and firmness to suit these changes as the car drives along.
Active Restraint – Something that restrains the movement of a passenger during an accident and which is attached or connected to the person. Usually refers to a seatbelt.
Advance – 1. To make the engine fire earlier during it’s cycle. 2. The degree to which the engine is made to fire earlier in it’s cycle. See also Timing.
Aerodynamics – Aerodynamics is the study of how objects move through the air. The smoother and more streamlined the shape, the less wind resistance you get. Car manufacturers measure how much resistance, or drag, there is, by referring to a Coefficient of Drag rating. Usually abbreviated to Cd. Cd gives you a rough indication of how much energy (read fuel) is required to push the car through the air at a given speed.
A-frame – 1. A part of some cars’ suspension which is shaped like the letter A sitting on it’s side. This is also known as a Wishbone. 2. A rig for towing one car with another one, shaped like the letter A.
Aftermarket – Extras such as alarms, alloy wheels, body parts, interior trim pieces, stereo equipment etc which do not originate from the car manufacturer and were not fitted to the car when it was built.
Airbag – A balloon-like bag which inflates as a passive protection device during a collision. Depending on how many airbags a vehicle has, and where they are located, they can greatly reduce the chance of injury in an accident.
Air Brake – A braking system operated by compressed air. Usually used on large trucks rather than on cars.
Air Cleaner/Air Filter – A device that cleans impurities from the air before it enters the engine. This makes the motor last longer and run more quietly.
Air-cooled Engine – An engine cooled by air alone, instead of water.
Airflow Metre/Sensor – An instrument which measures how much air is flowing into the engine. Usually in order to pass this reading onto an EFI computer which then adjusts the air/fuel mixture to suit.
Air/Fuel Mixture, Air/Fuel Ratio – Car engines work by burning fuel. The more efficiently you burn the fuel, the more power you get and the less fuel you use in a given distance. Getting the exact right amount of air mixed in with the fuel before you ignite it is a key factor in gaining efficiency. This mixture is known as the Air/Fuel Mixture or the Air/Fuel Ratio.
ALB – Anti Lock Brakes. See Anti-skid Braking
All-Wheel-Drive(AWD) – A car driven by all of its wheels. Since most cars have 4 wheels, this term has come to be synonymous with Constant Four Wheel Drive. That is, a vehicle that is always putting power to all four wheels, rather than needing 4WD to be selected manually. See also Part Time 4WD and On-Demand 4WD for further explanation.
Alternator – A device attached to the engine that produces electricity to charge the car’s battery as well as running the lights, interior fans and any other items requiring electricity on/in the car. Technically, an alternator is a form of generator. An alternator has this name because it produces alternating current. As opposed to the dynamo generators installed in some older cars which produced direct current. These days, for simplicity, we refer to a DC producing generator as a generator, while we refer to AC producing generator as an alternator.
Amperes(Amps) – A measurement of a unit of electrical current. An amp is the amount of current produced by 1 volt acting through 1 ohm of resistance.
Amp Hour, Amp/Hour – Amps per hour. A measurement of energy usage and efficiency.
Analogue Instrument – An instrument ( a speedometer for instance) which displays it’s information by moving a needle around a dial. A clock with hands is an analogue instrument for instance.
Anchors/Anchorage Points – 1. A mounting point on the vehicle for such things as seatbelts/child seat holders. The Anchor point must be a particularly strong part of the car’s body or frame and they are often reinforced, because they have to hold up well in the case of a car impact/accident.
Anti-Dive – When you hit the brakes hard, your car will dip or dive forward towards the road as the weight transfers. An Anti-Dive suspension setup will resist this urge to dive by stiffening up the front end of the car, either via the dampers, the springs or through a third specific-to-the-job system.
Anti-foaming Agent – Engines use oil to make the insides slippery. This is necessary for lubrication at the speeds engine internals operate. Engine internals churn and slosh the oil though, causing it to foam. Foamed oil does not work as well as it should and engine damage could occur. For this reason, oil companies add an Anti-foaming Agent to the oil to prevent the problem.
Antifreeze – A liquid which stops the water in your car’s radiator and engine from freezing during extreme cold conditions. This usually also includes a rust inhibitor to stop corrosion from eating away at your engine’s internals.
Anti-knock Agent – Chemicals added to petrol to raise their octane levels and reduce the chances of engine knock/ping.
Anti-Knock Index – See Octane Rating.
Anti-Roll Bar/Roll Bar – A part of a car’s suspension that helps reduce body roll during cornering.
Anti-Skid Braking – A braking system that uses sensors to detect when a wheel is about to lock up during braking. The brake controller(usually electronic) then let’s the brake off just enough on that wheel to prevent lock up and then applies it again. It continues like this, on and off, so that the tyre does not skid on the road surface. This improves control as a tyre which is not skidding can still be turned, which means the car can still be steered under heavy braking.
Anti-squat Suspension – A suspension setup which prevents the rear of the car from dropping too far under acceleration.
Anti-Sway Bar/Sway Bar – A part of a car’s suspension that helps contain a car’s lateral movements. Literally prevents the car from swaying side to side.
Anti-Submarining Device – A steel ramp or tube in the seat frame that prevents the occupant from slipping under the seatbelt during a heavy impact.