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A Glossary of Automotive Terms

A car is defined as a road vehicle powered by an internal combustion engine (ICE). Modern cars and automobiles typically have four wheels and are used to transport passengers from point A to B.

This section is an alphabetical dictionary of car terms with basic explanations of car jargon and slang words used in the motoring industry.

What Does All this Car Terminology Mean

Why does it matter whether it's called an SUV or a Crossover and is there really a difference?

When is a four-wheel drive MPV a soft-roader instead of a 4WD CUV off-roader?

We aim to simplify the basic car parts glossary with easy to learn and understand concise explanations of all the vehicle facts you need to know.

As we drive you through the 'fog of car terminology' the key terms and phrases should become less of a grey horseless carriage and more of a shiny new limo.

This alphabetical glossary of automotive terms should help to explain the meaning of car jargon and slang words.

Check out the mechanical phrases used in the motoring industry - from A Cheap Banger to a Bentley Zagato.

CAR TERMS: 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

Anti-Lock Brakes (ABS)

Anti-lock braking systems are fitted to most modern cars to prevent the wheels from locking when braking in an emergency.


To slide out of control on a wet road surface.

Automated Emergency Braking System

Abbreviated to AEB, automated emergency braking is a safety system that's able to identify when there is a potential for a collision. If so, the response will be to "autonomously" activate the brakes, which in turn, should slow down - or completely stop - the vehicle.

By and large, the technology uses a camera, radar, or Light Detection and Ranging (LiDAR) remote sensor method. When a vehicle is travelling slowly, the automatic emergency braking system can usually bring it to a complete stop and prevent a road collision.

Automatic Gearbox

The transmission will automatically select gears as the driver accelerates and decelerates.


A vehicle axle is a rod or spindle (sometimes called a shaft) which passes through the centre of a wheel or group of wheels.

Axles may be either fixed or rotating on wheeled vehicles. To assist rotation, bearings or bushings are usually fitted at the mounting points where the axle is supported.


Unless you are really into your pickup trucks you are unlikely to know what bakkie means?

In simple terms the definition of bakkie is a small truck with low sides and an open body. The term 'bakkie' is synonymous with van, lorry, or pick-up truck.

Benefit in Kind (BIK)

A 'Benefit in Kind' or BIK is otherwise known as company car tax and regarded as actual monetary value which is not included in your salary - such as a company car.

A vehicle becomes a taxable perk of the job (BIK) if it is supplied to you in connection with your employment and you use it for private transportation.

That also includes the car fuel benefit made available for any personal or recreational trips.


Blow-by, also known as compression blow-by refers to the leakage of air-fuel mixture or the combustion gases taking place between a piston and the cylinder wall and entering into the crankcase of an automobile.

Blow-by increases when various factors influence the leakage such as bad ring profile, an oversize bore, dents on the piston, and late opening of the exhaust valves.

Body-on-Frame Chassis

Often called "ladder frame construction", body-on-frame is a type of construction used in the manufacture of motor vehicles.

In simple terms, constructors mount a separate body or coach onto a strong chassis. The rigid framework carries the engine and drivetrain (powertrain) and several other access points for mounting the wheels, suspension, brakes, and the steering system.

Boxer Engine Configuration

Most flat engine cars, such as the classic Alfa Romeo 33 models, use the powerful "boxer" configuration. In other words, pairs of opposing pistons move inwards and outwards at the same time.

The car terminology comes from the similarity to competitors punching their boxing gloves together before they start boxing.

The outcome of using the boxer engine configuration is low vibrations due to the lack of unbalanced forces, no matter how many cylinders. So, a boxer engine doesn't need a balance shaft or any counterweights on the crankshaft.

Brake Fade

Where brakes lose their effectiveness due to overheating and over-use.

Brake Horsepower (BHP)

This is the measurement of a car's horsepower when it comes straight out of the crankshaft. Horsepower is often lost as it is transmitted from the crankshaft and through the gears.

So the horsepower that is delivered to the wheels is usually less than what is produced by the engine.

Bull Bars

A bull bar is a sturdy device fitted to the front of a vehicle. The aim of 4x4 bull bars is to protect the vehicle from front collisions.


A car (aka motor car) is defined as a road vehicle which is powered by an internal combustion engine.

Modern cars and automobiles typically have four wheels and are used to carry a small number of people from point A to B.


This is a component that mixes the fuel and the air.

Car Handling

How responsive and accurate the steering is. If you were driving through a bend and you needed to make constant alterations to the steering wheel then you could say the car had bad handling.

If the car went exactly where you steered it, even at high speeds, then the car would be considered to have good handling.

Catalytic Converter

A gadget fitted to the exhaust system that reduces pollution by turning harmful gases into less harmful ones.


The structure that acts as a mounting to the major car parts i.e. suspension system, frame, wheels and body.


The clutch enables the engine to be disconnected from the transmission in order to engage or disengage the gears.

Common Rail

Common rail is a direct fuel injection system used in petrol and diesel engines. Specifically on diesel engines, common rail features a high-pressure (over 1,000 bar or 100 MPa or 15,000 psi) fuel rail feeding individual solenoid valves, as opposed to a low-pressure fuel pump feeding unit injectors (or pump nozzles).

Continuously Variable Transmission (CVT)

An automatic gearbox with CVT is one that weighs less than a traditional automatic gearbox. In general, being lightweight with smoother operation (lack of gearing) means it can improve the fuel efficiency for vehicles with CVT.


A car with a folding, removable, or a retractable roof. Also known as a cabriolet.


A coupe car that is often the sports version of a saloon car. Typically they have 2 doors and are less spacious in the rear.

Coupé Utility

The simple definition of a coupé utility is a vehicle with a passenger compartment at the front and an integrated cargo tray at the back. For the most part, the front of the cargo bed also doubles with the rear of the passenger compartment.

Even though the term "coupe utilities" originated way back in the 1930s, it's generally used to describe a pickup, car-based pickup (e.g. the Volkswagen Saveiro), or even a car-based truck in the present day.

Crankcase Breathers

Excessive diesel smoke from the crankcase breather indicates a severe engine problem. It is most often caused by worn or broken piston rings allowing gases from the cylinders to pass into the crankcase.

Ultimately, the gases leak out into the atmosphere via the crankcase breather.

Crossover Utility Vehicle (CUV)

What is a crossover SUV? A crossover utility vehicle (CUV) is an automobile which is built on a car platform and combines the general features of sports utilities (SUVs) with those of passenger vehicles.

The most noticeable of which are those characteristics which are similar to a hatchback or station wagon, but crossovers are generally smaller than a full SUV or large MPV.

What is the difference between a CUV and SUV? Crossover utility vehicles are built using the unibody construction which is typical of a passenger vehicle as opposed to that of the body-on-frame platform used in light trucks (and original SUVs).

Smaller models may only have seating for only four people (compact-CUV) whereas other versions can only accommodate two people, despite their appearance of a tiny truck.

As a rule, crossovers combine the design features which are typical of SUVs such as tall interior packaging, high centre of gravity (H-point) and ground-clearance, with all-wheel-drive capabilities.

Add to that, independent rear suspension, car-like handling, and superior fuel economy, and you have the classic ingredients for a modern day CUV.

Despite all this technobabble, crossovers often include the two-box design with rear access via a door or liftgate with passenger and cargo volume enhanced by fold-down rear seats.

Perhaps the biggest advantage of driving a crossover is having the choice between front, rear, or all-wheel drive configurations. That said, they are typically designed for light off-road capabilities.

Popular crossover vehicles include the Nissan Pathfinder, Lexus RX, Explorer, Highlander and Grand Cherokee, and the Acura MDX.

Diesel (engines)

The easiest way to remember how a diesel engine works is by remembering the phrase "suck, squeeze, bang, and blow". This refers to a cycle of 4 strokes known as the OTTO cycle.

Diesel Fuel Water Separators

A diesel fuel water separator is a simple gadget which is attached to your diesel engine and works by collecting water from the fuel system. The device is normally found on or near the fuel filter in the engine bay.


The D-pillar is the roof support structure on a minivan, wagon, or SUV and located at the rear of the vehicle.

Dual Overhead Camshaft (DOHC)

The actual location of the camshaft has several variations in car terminology (automotive terms). If the camshaft location is in the cylinder head above the combustion chamber it is an overhead camshaft (OHC) engine (not an overhead valve).

So, twin cams, also called Dual overhead camshaft engines (abbreviated to DOHC) have two (2) camshafts per bank.

Pro Tip: The first car to be powered by a DOHC engine was a Peugeot inline-four racing engine. The car went on to win the French Grand Prix in 1912.


E85 is a fuel consisting of gasoline or another hydrocarbon and then mixed with quantities of denatured ethanol up to 85%.


A vehicle's emissions are measured as an amount of CO2 in g/km for company car tax purposes and relates to the amount of gas emitted from the tailpipe exhaust.

Engine Coolant

Liquid in the radiator that removes heat from the engine.

Engine Litre Size

You may have seen a car advertised or referred to as say a 1.2 litre. What this means is the engine size, or more accurately, the space that is available inside the engine's cylinders for the fuel-air mix.

The greater the space the greater the amounts of fuel-air mix which ultimately means more power.

One cylinder may have a space of 0.5 litres however the engine may have eight cylinders, which would give an engine size of 4 litres. This measurement is also known as engine displacement.

Estate Car

Has an extended rear cargo section and the full height of the car extends to the boot, which gives a much larger storage space.

Exhaust Emissions

Gases that are expelled from the exhaust pipe.

Four Wheel Drive (4x4 or 4WD)

Four-by-four, also called 4x4 or four-wheel drive, refers to the delivery of power to all four wheels from the engine. When four powered wheels are engaged it helps to stabilise the car's handling and maximises road grip.

All other things being equal, having four-wheel drive generally makes a car or truck safer when changing direction, and especially in slippery or icy conditions.

Therefore, 4x4s are less likely to get stuck in mud, sand, gravel, or thick snow. The principle reason for this, and other off road capabilities, is all four wheels receive power so they all help dig for traction.

Despite this, some 4x4 systems are driven using two-wheel drive during regular driving. The vehicle automatically chooses between two-wheel drive and four-by-four, or the driver can make the selection.

Alternating between the two drives is achieved by levers, switches in the cabin, or by getting out and adjusting the wheel hubs such as in certain trucks.

Front Wheel and Rear Wheel Drive

Most cars have front wheel drive. This is where the power is sent to the front wheels and these in turn drive the car. Rear wheel drive cars are usually much better handling but also tend to be the more expensive cars to buy.

Fuel Consumption

The amount of petrol or diesel that your vehicle uses.

Fuel-Injection System

A computerised system that mixes the fuel and air before it passes into the engine for combustion. Such a system is more efficient than a standard carburettor.

Gas/electric Hybrid Engine

A gas/electric hybrid engine is a powertrain combining an electric motor and a gasoline (or diesel) internal combustion engine.


Gearing is used to control the speed of the engine in relation to the vehicle's speed. In low gear the vehicle runs more slowly, in high gear more quickly.

Glow Plugs

The basic function of glow-plugs is to provide diesel engines with additional heat energy during start-up in cold weather. In simple terms a glow plug is an electric heating device.

Haldex Clutch

Haldex clutch refers to the limited slip coupling used in vehicles with automatic all-wheel drive systems. They are used to engage and disengage a secondary axle when it is utilised.


Are often like estate cars but have a much smaller boot, which can always be accessed from the rear seats.


Her Majesty's Revenue and Customs is the tax authority in the United Kingdom.


Complicated this one but basically an inventor called James Watt calculated that one horse could do 30,000 foot-pounds of work in one minute.

He applied this measurement to steam engines and the measurement has been used to quantify the power of engines ever since. So horsepower is the measure of an engine's power.

Hybrid Cars

In simple terms, the definition of hybrid cars are those vehicles which achieve maximum power and fuel economy by using multiple, and different, classes of on-board energy systems.

Therefore, typically a hybrid vehicle comprises one or more electric motors (with battery packs) as well as a small size traditional internal-combustion engine (ICE) and a fuel tank.

Idle Speed

Idling speed refers to the revolutions per minute (RPM) of the engine when it is free from load (all accessories off). The idle speed is calculated at normal operating temperature and in neutral gear (park or neutral for an automatic transmission).

Injector Servicing

Prolonged injector malfunction can cause major engine damage. Injectors should be serviced regularly by a reputable diesel specialist and according to the manufacturer's recommendations. Injector servicing typically checks for;

  • nozzle leakage or dribbling
  • correct injector for the vehicle and atomisation
  • correct opening pressure and back leakage

Inline-Four Engine

In mechanical phraseology, an inline-four (or straight-four engine) refers to a four-cylinder piston engine whereby the arrangement of the cylinders is in a "straight" line running along a common crankshaft.


Isuzu is famous for building commercial vehicles that move heavy loads to the most difficult destinations. Their unmatched powerful diesel engines provide essential power to help support road cargo and off road deliveries.

Having expanded their operations outside of Japan, Isuzu Motors now benefits drivers in more than 100 countries around the world.


Keyless Ignition

Keyless ignition systems, such as in the Chevrolet Suburban, allow the activation of a push-button to start a vehicle by the driver. Keyless ignition only works when the proximity sensors detect the electronic key inside the vehicle.

Lane Departure Warning System

A lane departure warning system is a combination of electronic components which are designed to warn a driver when a vehicle strays out of its carriageway or lane.

Limited-Slip Differential

The original creation of limiting wheelspin dates back to Grand Prix cars in 1935. Nowadays, having a car with a limited-slip differential (LSD) is also going to help improve traction.

So, if your vehicle has an LSD system, it switches up the torque sent to each wheel. Hence, being able to better maintain a full grip on the road is handy during track days and for driving off-road.

Limited slip systems are more common on 4x4s and sports cars (e.g. to improve handling and performance). So, if we define LSD in simple car terms, the setup limits the amount of slip from the wheels so the driver can apply proper power.


Lugging the engine is a car term referring to the labouring of the engine in too high a gear. Because it can cause excessive smoke emissions, drivers should be familiar with the minimum engine speed required to avoid smoke emissions.

Overloading a vehicle or operating the engine 'on the governor' (that is, at maximum RPM) may cause excessive smoke emissions especially when performed for long periods of time if prevailing conditions require less.

Manual Gearbox

Where the driver physically selects the gears themselves.

Mid Wheel Drive (MWD)

A vehicle with a mid-wheel configuration, such as the Daihatsu Hijet, has the drive wheels positioned in the centre of the power base. Hence, center of gravity for the driver is almost even with the center of the drive wheels.


In car terms, a monocoque chassis refers to the structural system (skin) used to support different loads around its vehicular structure or shell.


A test to check that your car is safe to drive.

Multi Purpose Vehicles (MPV)

Multi-Purpose Vehicles (MPVs) were known as the early people-movers and most likely termed that from the 'minivan people-mover'.

They were usually vans, or large pickup trucks with extended cabs, and typically had a seating capacity for seven passengers.

The first van-style seven-seaters were called MPVs - first labelled as such by Mazda.

Natural Gas Engine

A natural gas engine is an internal combustion engine which burns natural gas to produce its power.


OEM is a term used to describe the original equipment manufacturer (i.e. the manufacturer of a vehicle).

Over Fuelling

Overfueling causes smoke emissions because the excess fuel that cannot be burnt is emitted as black smoke.

Adjusting the fuel system in an attempt to increase the power output of an engine (often too small for the job) or to compensate for power loss in a worn or poorly maintained engine, will lead to more fuel being injected into the combustion chamber than the engine can efficiently use.


If when driving through a bend and the rear wheels fail to follow the front wheels and instead veer towards the outside of the turn, you are experiencing oversteer.

P11D (form and value)

The form P11D is the document which must be completed by an employer every year and returned to HMRC.

The P11D value refers to the total value of a vehicle including the Recommended Retail Price, Value Added Tax, and any optional extras or accessories such as satellite navigation, metallic paint, or parking sensors.

Petrol (engines)

Here is a very simple way to remember how a petrol engine works. It uses a cycle of 4 strokes commonly referred to as "suck, squeeze, bang, and blow".

Pickup Truck

The definition of a pickup truck is a light motor vehicle with a rear cargo area which is open at the top. Countries have created their own distinct terms for pickups, such as the 'ute' or utility vehicle in Australia and bakkie in South Africa.


Most car experts agree that it is the vehicle's platform which differentiates a crossover from an SUV. A crossover is based on the same platform as a car, meaning the body and frame are one piece (referred to as 'unibody' architecture).

Whereas SUVs generally have a similar chassis to a truck called 'body on frame' design. This means that the body is built separately from the main frame and two structures are placed together after their individual construction.


The powertrain is the mechanism which transmits the drive from the vehicle's engine to the axle.

Power Steering

Makes turning the wheels a lot easier. Means the car has a separate power source that helps turn the wheels.


Radiator Hoses

What is a radiator hose? In simple terms, car radiator hoses are tubes which connect the radiator and the engine, but there will be more than one hose in a given mechanical system. The top of the radiator connects to the top of the engine by an upper hose.

A lower hose is used to connect the bottom of the radiator to the water pump, which is the device that keeps coolant flowing throughout the system.

Recommended Retail Price (RRP)

This car term refers to the amount of money that the car manufacturer recommends selling the car to be.

Saloon Car

A car with 2 front seats, at least 2 rear seats, four doors and a separate boot.


In fact, the shift-by-wire concept has been commercially available since 1996. By and large, it's used in automated manual transmission systems and some semi-automatic transmissions, such as in the latest Volkswagen Amarok pickup truck.

In simple terminology, the electronic automotive system known as shift-by-wire replaces the mechanical connection between the gearshift mechanism and the transmission.


When the tyres fail to grip the road, the subsequent loss of control of the vehicle's movement is called a skid. Often caused by harsh braking or steering, or driving too fast.


Sludge in car oil can cause a significant loss in power, poor oil pressure, an increase in lube usage, overheating under load, blow-by, and dirty exhaust smoke. The black tar like oil sludge affects diesel and petrol engines.

Smoky (diesel engines)

Diesel car engines get smoky for many reasons but identifying the smoke colours, often white or black, helps you diagnose the cause of the problem to hopefully cure and stop a smoking diesel engine.

Softroaders (crossovers)

A soft-roader rarely has the same short overhangs or increased road clearance to conquer the full blown heavy off road tracks.

Nonetheless, SUV or wagon soft-roaders will typically perform a step above regular cars on snowy roads or light muddy trails because of their suspension adjustments and skid plates.

Perhaps for this reason, most are referred to as 'crossovers', and a typical example of a softroader would be the Citroen C-Crosser.

Sports Utility Vehicle (SUV)

A Sport Utility Vehicle (SUV) is an auto similar to a station wagon or estate car equipped with four-wheel drive to provide on-road or off-road capabilities - some owners call their 4x4 an 'action utility vehicle'.

What helps to make 4x4 SUVs special is that many of them offer the handy towing capacity of a pickup truck conveniently combined with the passenger-carrying space of a large family sedan or spacious minivan.

Sports utility vehicles are undeniably large and rugged, easily handling rough surfaces and extreme terrain.

Add to that a 4x4 auto which is never out of place on multi-lane highways and urban city roadways.

Built on a light-truck chassis, the term SUV is synonymous with almost any car which delivers all-wheel drive and raised ground clearance. SUV examples include the Chevrolet Tahoe, Ford Expedition and Mercedes G-Class.


A tachometer is a vehicle's instrument which informs the driver how fast the engine is rotating. Tachometers usually incorporate a red warning line to indicate the maximum engine speed available.


Torque is a measurement used to quantify the force of the rotational force produced by the engine. It is another way to measure the power of a car and is calculated in foot- pounds (ft-lbs).


These help an engine produce more power. A turbocharger uses the pressure from the exhaust to create more pressure in the cylinders, which enables them to receive more fuel-air mix.


Universal joints, also called u-joints, are flexible joints used on drive shafts. As a rule, they are composed of two U-shaped yokes which share a common cross-shaped member.


If when driving through a bend the steering wheel doesn't turn the wheels as much as you want then the car has understeer.

Vacuum Lines and Hoses

Vacuum lines and hoses are described as flexible tubing which is used to carry and move around fluids, air, vapours, or pressurised gas.


Each cylinder has valves; ones that allow the fuel-air mix in (intake valves) and ones that allow the exhaust fumes out (exhaust valves). Every cylinder needs at least one intake and one exhaust valve.

However some cars have more than one of each as more valves allow more fuel-air mix which helps to increase power and performance. A 16-valve engine is likely to have four valves on each of its four cylinders.

Variable Geometry Turbocharger (VGT)

Some turbochargers, often called variable-nozzle turbochargers (VNT), allow for alterations in the effective aspect ratio (A/R ratio) as conditions change.

In other words, adjustable vanes inside the turbine housing (between the inlet and the turbine) can change the flow of gases towards the turbine. Doing so has benefits for the optimum aspect ratio, especially at low engine speeds.

Vehicle Excise Duty (VED)

Vehicle Excise Duty (usually called road tax) is the amount payable on all cars, including company car tax, and broadly calculated on the vehicle's CO2 emissions.

Water Pump

A water pump is a mechanical device that circulates coolant through the cooling system of a vehicle.

Wheel Balancing

Wheels need to be balanced correctly as this allows them to rotate smoothly at all speeds.

Wheel Spin

When the vehicle's wheels spin round out of control with no grip on the road surface.

Wynn's Oil Treatment

Wynn's Super Charge Oil Treatment is suitable for both petrol and diesel engines. It is a product which helps to stop excessive oil consumption and restore engine compression.

Wynn's may also increase oil pressure. It is compatible with all mineral and synthetic, single- and multi-grade oils and does not harm catalytic converters. The features include:

  • Stops excessive oil consumption and improves engine performance.
  • Strengthens the oil film (especially at high temperatures).
  • Restores engine compression and increases the oil pressure.
  • Quietens a noisy engine and reduces exhaust smoke.
  • Provides a perfect lubrication of heavily loaded engines (e.g. when towing a caravan, in the mountains, on the motorway, at high temperatures, etc.).




ZEV is a three letter acronym which stands for zero emission vehicle. It is recognized as the most restrictive emissions standard in the motor industry.

We hope you found this alphabetical glossary of automotive terms and car definitions useful. We welcome all constructive feedback. Please contact us if we missed anything to add in this car terminology dictionary.

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