Automotive Glossary

[Praveen]

All the automotive jargon are explained in this thread. Do keep expanding it by adding information that may have been left out. Feel free to edit it if any of the information given is incorrect.

• ABS—Anti-lock Braking System:

This system helps the vehicle to slow down gradually. In a conventional braking system, the wheel tends to lock during hard braking. In a system with the ABS, there is a sensor which detects incipient wheel locking and applies the brakes in such a way that the wheel slows down without locking, thereby eliminating the chances of skidding and reduces the braking distance significantly.

• Active Ride Control:

This system is used to counteract the forward and backward pitching when a vehicle goes over a bump. The sensors detect the pitching and control the torque to the wheels accordingly through braking.

• Active suspension:

In a passive suspension, there are springs, dampers and tyres which react automatically to the road undulations. But in an active suspension, there are hydraulic actuators which control the movement of the suspension and wheels relative to the chassis or body rather than the road undulations.

• Anti-roll bars:

Anti- roll bars reduce the vehicle roll and increases the stiffness of the vehicle. The bars connect the opposite wheels of the vehicle. These bars help in better cornering while compromising on the ride quality.

• AT-- Automatic transmission:

It is a type of vehicle transmission that can automatically change the gear ratios as the vehicle moves, thereby eliminating the need to shift gears manually. Usually, such a gearbox is marked with ‘P R N D’ meaning Park, Reverse, Neutral and Drive respectively.

• Air-fuel ratio:

It is the mass ratio of air to fuel which is sent into an internal combustion engine. If exactly enough air is sent to burn up all the fuel inside an engine, then the mixture is known as ‘Stoichiometric mixture.’ If the air-fuel ratio is lower than stoichiometric ratio, then it is called as ‘rich mixture’ where the quantity of fuel is more than air and in a ‘lean mixture,’ the quantity of air is more than the fuel. When the air-fuel ratio is more than the stoichiometric ratio, then it is called ‘lean mixture.’

• A- Pillar:

A-pillar is one of the pillars which supports the roof and encloses the windshield of a vehicle.

• Adaptive cruise control:

It is a type of cruise control which is supplemented by a radar or a laser system which helps the vehicle to slow down automatically if there are any vehicles ahead so as to avoid collision.

• Angle of approach:

It is the steepest angle between an angled surface and a leveled surface onto which a vehicle can be driven without its forward overhang making contact with the inclined surface.

• Angle of departure:

It is the steepest angle between an angled surface and a leveled surface onto which a vehicle can be driven without its rear overhang making contact with the inclined surface.

• AUX—Auxiliary input:

It is a feature which helps in connecting a phone or any other electronic device that has provision for an audio jack with the car’s media system.

• AWD—All Wheel Drive:

It is a type of drive-train which employs a front, centre and a rear differential powering all the four wheels of a vehicle.

• Belt drives:

Belt drives are used to transmit power from one shaft to another parallel shaft by means of a flexible belt. They are also used in bikes like Harley Davidsons. The advantage of belt drives is that the mechanical losses by friction is lesser than chain drives and it requires lesser lubrication than chain drives.

• B- Pillar:

It is one of the pillars which supports the roof and is located between the front and the rear doors of a vehicle.

• BHP—Brake Horse Power:

It is a unit of measurement of an engine’s power at the output shaft. It is basically how fast an engine uses its capabilities. A typical family car cannot out-accelerate a sports car because of the difference in the horsepower. More horsepower equals higher top speeds.

• Blind-spot:

It is the area around the vehicle which is very hard to see in side or rear view mirrors.

• C- Pillar:

It is a support structure that is located next to the A- Pillar. It usually supports the car's roof and also acts as a structure for the front door latch and rear door hinges.

• Camshafts:

A camshaft is a shaft with cam-lobes. The lobes are attached to the valves and the rotational movement of the camshaft results in up and down movement of the valves. Therefore, camshaft helps in the opening and closing of valves in an engine.

• Carburettor:

A carburettor is a device which mixes air and fuel and sends it to an internal combustion engine. They are usually found in petrol engines.

• Chassis:

The chassis is the internal framework of a vehicle on which the body is mounted.

• Central Locking:

Central locking is a feature which allows the driver to simultaneously lock all the doors of a car, thereby eliminating the need to lock the doors individually.

• Chain drive:

Chain drive is used for the transmission of power from the engine to the wheels by means of a chain and sprocket. It is commonly used in bicycles and motorcycles.

• Catalytic converter:

It is a device which controls emission by catalysing the redox reaction of the exhaust gases. It basically lessens the toxicity of the exhaust gases.

• Child Seat:

A child seat is a type of car safety seat which is specifically designed to protect children in case of an accident or crash.

• Clutch:

It is a device which engages the transmission. It engages or disengages the driving shaft (from the engine) to the driven shaft (gearbox).

• Convertible:

A convertible is a type of car body style in which the roof of the car is retractable can therefore convert into an open-top or a closed one. The conversion can either be a manual or an automated one.

• Climate Control:

It is the ‘smarter’ version of standard air-conditioning. Climate control keeps the inside of a car to the user-set temperature no matter what the outside temperature is.

• Cruise Control:

Cruise control is a function which, when activated allows the user to maintain a particular speed.

• CVT (Continuously Variable Transmission):

It is a type of automatic transmission which uses belt driven conical pulleys, thereby resulting in a seamless change of gear ratios.

• Cylinder Deactivation:

Cylinder deactivation is a feature in modern cars which allows one or more cylinders can be deactivated to improve fuel efficiency, but at the cost of performance.

• Crumple Zone:

It is a structural feature of a vehicle which deforms on impact, thereby absorbing the impact energy in a controlled manner.

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• D- Pillar:

In large vehicles like SUVs or Estates the supporting structure after the C- Pillar is called the D- Pillar.

• Differential:

A differential is a part of the drivetrain which has a set of gears. It drives a pair of wheels and allows them to rotate at different speeds.

• Direct Injection System:

There is a fuel injector which sprays fuel in the combustion chamber, unlike a traditional engine where the fuel goes through the air intake manifold. This is called direction injection system.

• Disc Brakes:

A disc brake is a type of brake in which a “disc” is attached to the wheel. During braking, the brake calipers squeezes the brake pads, and slows down the disc by friction.

• DSG (Direct Shift Gearbox):

The DSG gearbox has two clutches that are mated to the engine – one that handles odd numbered gears and one that handles even-numbered gears. This system uses as series of electronic motors to activate the clutches and perform the gear shifts, thus the gear shifting speed is faster than conventional gearboxes.

• Displacement (Engine):

Displacement is the volume swept by all the pistons inside the cylinders of a reciprocating engine. It is usually measured in Cubic Centimeters (CC) or Cubic Inches (Cu In)

• Drive Shaft: or Propeller Shaft:

It is a rotating shaft which is connected to the engine and differential. It transmits the torque and rotation from the engine to the differential.

• Electronic Brake Force Distribution (EBD):

In some ABS equipped vehicles, there is a feature called the EBD, which basically distributes the braking force independently to different wheels of the vehicle. The force of the braking varies depending on the road condition, traction level, speed, etc.

• Electronic Stability Program (ESP):

It is a computer-based technology which detects a vehicle's loss of traction and improves the stability accordingly by modulating braking and “steer” the vehicle in whichever direction the driver wants to go. It basically minimizes the loss of control.

• Emergency Brake Assist:

It is a braking technology which increases the braking pressure in case of an emergency. The system detects if the driver is trying to panic brake and if the brake is not fully applied, the system amplifies it until the brakes are fully applied. In case if the Emergency Brake Assist is coupled with the ABS unit, then the braking force is applied until the ABS kicks in to prevent the wheel from locking.

• Engine Oil:

Engine oil is basically an oil-based lubricant that reduces the friction, wear and tear in the internals of an engine and helps keeping it cool by carrying the heat away from the moving parts.

• Engine Auto Start-Stop:

Engine auto start-stop system is a system which shuts down the engine when it is idling for a brief period of time and starts the engine again when the clutch is pressed or when the brake is released. It is to be noted that the transmission is to be in neutral in manual cars and the transmission should be in 'Drive' in automatic cars.

• Factory Installed/ Factory Fitment:

Any part or accessory that is installed by the manufacturer when the car is made in the factory is called “Factory Installed” or “Factory Fitment”.

• Fog Lights:

Fog lights are usually mounted at a low level on a car's bumper. These lamps cut through the fog and help illuminating the road better on foggy days.

• Flex Fuel Engine:

An internal combustion engine that is capable of running on more than one type of fuel is called 'Flex Fuel Engine'. The fuels are usually petrol and ethanol or methanol fuel.

• Forced Induction:

Forced Induction is the process of delivering compressed air into the intake of an internal combustion engine. It is usually done using gas compressors.

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* G- Force:
It is the force exerted on the vehicle when it accelerates/ decelerates/ goes around a corner. It is usually measured by the unit of gravity, which is G.

* Gas Filled Shocks:
It is a type of shock absorber which uses pressurized nitrogen gas to compress the fluid in the shock so as to prevent it from foaming or aeration while the shock is in action.

* Gasket:
Gaskets are usually made up of soft materials that are compressible and are placed between two metal parts in order to seal them.

* Gear lubricant:
A special type of oil used to lubricate the gears in a transmission unit. It is usually much thicker than the engine oil. Similar type of oil is also used for the differential as well.

* Gear ratio:
Gear ratio is the ratio between the speed of the driving gear and the driven gear. The driving gear is mated to the engine crank and the driven gear is mated to the output shaft.

* Gel seat:
An ergonomic seat, made up of a gel-like material which distributes the rider's weight equally, thereby improving comfort by increasing the blood circulation. As a result, the fatigue is also reduced.

* GT- Grand Turismo:
It means Grand Tourer in Italian. It is basically a high performance car capable of high speed long distance runs as well.

* Ground Clearance:
The minimum distance between the ground level and the lowest point of a vehicle.

* Headroom:
Headroom is the distance between the surface of the seat and the roof surface in the interior of a vehicle.

* Heads Up Display (HUD):
HUD is display projected from the dashboard onto the windshield of a vehicle, without deviating from the driver's line of sight. It displays vital information such as speed, rpm, fuel level, etc.

* Hill Hold Control:
Hill hold is a feature which holds the brake pressure even when the brakes are released when the car is on an incline.

* HVAC:
HVAC stands for Heating, Ventilation, Air Conditioning. It is a term used to describe the technology used in a vehicle for controlling the environment inside.

* Hybrid Vehicle:
A hybrid vehicle is a type of vehicle which uses two power sources, in most cases it is a combination of internal combustion engine, battery with electric motor, or fuel cells.

* Hydrogen Fuel Cell:
It is a type of fuel cell in which electricity is produced between two electrodes by the exchange of hydrogen and oxygen ions.

* Idle Speed:
Idle speed is the rotational speed of the engine crankshaft when the engine is not coupled to the transmission and when there is zero throttle input.

* Idle speed adjuster:
It is a screw in a carburettor which adjusts the idle speed of the engine by changing the ratio of air fuel mixture.

* Ignition Timing:
Ignition timing is the timing at which the spark plugs produce a spark to initiate combustion inside in the engine cylinder. It is measured in degrees of crankshaft rotation.

* Ignition Coil:
Ignition coil is a transformer that steps up the voltage of the battery to thousands of volts so as to necessitate the production of spark from the spark plug for combustion.

* Integrated turn signal:
It is a feature where the turn signal lights are mounted on the rear view mirrors. It is usually done to improve aesthetic appeal.

* Intake manifold:
It is a part of the engine, usually a piping system which feeds in fuel air mixture to the engine cylinders.

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* Juddering:
A type of low frequency vibration caused when the clutch slips or when the vehicle goes over a series of bumps.

* Jump start:
It is an engine starting technique which is done by connecting the car’s battery terminals using jumper cables (heavy duty cables) to another car’s battery terminals.

* Jack:
A jack is a device used for lifting heavy objects. A jack is normally mounted at specific points of a vehicle designed for jacks.

* Keyless entry:
It is a feature in a vehicle which allows a person to access the vehicle using an electronic remote key instead of a traditional key.

* Kerb weight:
It is the weight of a vehicle with 90% fuel and all other fluids onboard.

* Knee room:
Knee room is the space available for a person’s legs (especially the calf region) when he/she sits in the rear passenger seat.

* Knock Sensor:
It is an electronic device which detects the knock in an engine and retards the ignition timing accordingly by sending signals to the Engine Control Unit (ECU).

* L- Twin engine:
An L- twin engine is usually used by Ducati. They cylinders are perpendicular to each other, thereby giving an L-shaped look.

* Ladder frame chassis:
It is a type of chassis in which the two longitudinal beams running along the length of the vehicle and a number of transverse support structures connecting the two parallel beams.

* Lane departure warning:
Lane departure warning consists of a series of sensors working in an electronic system which warns the driver when the vehicle moves out of its lane without proper signalling.

* Limited Slip Differential:
It is a type of differential unit which allows the wheels to spin at different speeds within a certain limit. It helps in reducing wheel spin by diverting the power to the other wheel (to a certain extent) where there is less traction available in one wheel.

* Lumbar Support:
The support offered by a seat to the lower back is called lumbar support.

* Launch Control:
Launch control is a feature offered in performance cars to help reduce the wheel spin and gain as much traction as possible when the vehicle accelerates hard from stand still.

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* Mid Engine Layout:
A vehicle with a mid-engine layout has the engine mounted behind the seat, but ahead of the rear axle.

* Macpherson Strut:
It is a type of suspension system in which there is a strut attached to the top of the wheel hub carrier and it consists of a damper with a coil spring. The upper portion of the damper spring is connected to the chassis.

* Maintenance free (MF) battery:
It is a type of lead acid battery which is completely sealed. Regular top up of distilled water is not required in a MF battery.

* Manifold:
A piping system which sends in air-fuel mixture to the engine and takes out the exhaust gasses from the engine.

* MSRP:
MSRP is expanded as Manufacturer Suggested Retail Price.

* Manual Transmission:
It is a type of transmission in which the gear changes are manually done using a gear lever and a clutch pedal. They are connected to their respective components which engage or disengage different gears and thereby vary the power and torque output of the engine to the wheels.

* Naturally Aspirated (NA):
It is a type of engine which does not use any form of forced induction like Turbochargers or Superchargers. Air is taken in normally through an air intake and air filter.

* Navigation System:
It is an electronic system which uses satellite signals to determine the position of the vehicle and uses pre loaded maps to help navigate the vehicle user to a particular direction.

* NCAP:
It is the full form of New Car Assessment Programme. It is a safety assessment programme where the vehicles are crash tested to see how well they can protect the occupants in a simulated collision. The results are rated out of five stars.

* Negative Camber:
In a negative camber, the suspension is designed in such a way that the top of the wheel is angled towards the body while the bottom portion of the wheel is angled away from the axle.

* Neutral:
A neutral gear is the one in which there is no transfer of power between the engine and the driven wheels.

* Neoprene:
It is an artificially made rubber which is more chemically and thermally stable than natural rubbers. It is used in gaskets and fan belts.

* Nm (Newton Meter):
It is a unit of torque measurement where one newton meter equals the torque produced when one newton of twisting force is applied perpendicularly at a distance of one meter from the wheel’s rotational axis.

* NiCaSil Coating:
It is a type of coating which involves a combination of Nickel, Calcium and Silicon. The coating is done on the insides of engine such as piston walls, etc. This reduces friction and also improves the reliability of the engine.

* Noise Vibration and Harshness (NVH):
Also known as NVH levels, it is a measure of refinement a vehicle offers. A vehicle with high NVH levels may compromise on comfort and may be distracting to the driver.

* Notchback:
It is a type of vehicle body style where, along with the boot, the rear windscreen is also capable of opening. Rear windscreen is hinged to the roof.

* Octane Rating:
Octane rating is a figure used to measure the performance of a fuel. The higher the octane rating, the more it withstands compression before igniting, thereby resulting in more complete combustion. If fuels with lower octane rating are used in high compression engines, it results in premature ignition called ‘knocking’.

* Oil Strainer:
It is a component which filters out the dust particles and other impurities and ensures the oil entering the oil pump is clean.

* On Board Diagnostics:
On Board Diagnostics is the vehicle’s capability to scan and diagnose its subsystems.

* Overdrive:
Overdrive is an additional gear which ensures comfortable cruising at low rpm without straining the engine. This results in lower fuel consumption as well.

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* Paddleshift:
It is a type of semi automatic transmission which uses a combination of electromechanical sensors, actuators and pneumatics to change gears when the user controls the paddles located on the steering wheel.

* PS (Pferdestarkes):
It is the power of an engine measured at the output shaft. It is 0.985 times of one horsepower.

* Particulate emission:
The emission of particulate matter from internal combustion engines is called particulate emission. They are unburned hydrocarbons which when inhaled, are harmful to the human body and may cause lung related ailments, etc. Particulate Matter (PM) is measured in microns.

* Pre Delivery Inspection (PDI):
It is a step by step quality inspection of a new vehicle before it is delivered to the owner. It is usually done by the dealer but it is advised the owner should do it as well.

* Pintle Pin:
It is a steel pin used to secure the tow hook.

* Power steering:
It is a type of steering system which uses electric or hydraulic actuators to turn the steering mechanism, thereby requiring less effort to turn the steering wheel.

* Quattro:
Quattro is an All Wheel Drive System used by Audi in their road cars.

* Quick release steering wheel:
It is a type of steering wheel that can be removed be pushing a button. It is normally used in racing cars. Sometimes it is also used in road legal cars to deter thefts.

* Radiator:
It is a device which cools the coolant by the principle of convective cooling effect (carrying the heat away from the source by a fluid)

* Radiator Fan:
It is a fan that cools the radiator unit.

* Rack and pinion steering:
It is a type of steering system where the end of the steering column consists of a pinion gear and it rotates over a flat rack gear system which turns the front wheels.

* Rain sensing wipers:
These wipers turn on automatically when it rains. It works on the basis of total internal reflection. In a rain sensing wiper system, there is a sensor which projects infra red light on the windshield. The light bounces off of it and gets reflected back into the sensor. When rain water is incident on the windshield, the infra red light gets scattered off and thus less light enters the sensor. Whenever this happens (until a particular level), the sensor activates the wiper.

* Radial Tyre:
It is a tyre design in which the plies are perpendicular to the direction of wheel travel. This offers better stability at the treads and flexible side-walls.

* Recall:
Recall is a corrective action taken by a manufacturer to fix its defective vehicles that may compromise on the safety of the user.

* Regenerative Braking:
It is a mechanism through which kinetic energy produced while braking is recovered in the form of usable electrical energy which recharges the battery.