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Displaying 201 - 250 of 502 glossary terms Use the search function to find terms.

Floorplan refers to the biggest part of the car's body. It is a stamped metal part that contains several smaller attached stampings. It is also called the foundation of the vehicle structure… Read more


These usually include the most common: Engine oil, Transmission Oil, coolant, Brake fluid, and hydraulic oil for the power steering. Follow the intervals of replacing those regularly.


Flywheels are mounted on engine crankshafts. Its outer part has a gear tooth which allows the starter to rotate it until the engine starts up. The flywheel holds the clutch pack and connects with… Read more


Frame is the structure that carries suspension, powertrain, and other components. There are several types of frames, one most common is the ladder frame in SUV's which had the cabin installed… Read more


Foot-Pound refers to a measurement of work or energy. One foot-pound (ft-lb) is equal to the work done when a force of one pound is exerted on a body that moves a distance of one foot in the… Read more

Fuel Capacity

Fuel Capacity is the amount of fuel that a vehicle's fuel tank can hold in a fuel tank.

Fuel Economy

The Fuel Economy of an automobile relates to the distance traveled by a vehicle and the amount of fuel consumed. A consumption rate can be calculated by dividing the amount of fuel used by the… Read more

Fuel Filter

Fuel Filters are filters installed in series with fuel systems that prevent small debris fragments from reaching injectors and combustion chambers. It prevents particulate matter and most… Read more

Fuel Injection

Fuel Injection is a device that atomizes the fuel by forcibly pumping it through a small nozzle under high pressure and delivering it to the vehicle's engine. Fuel injectors are responsible… Read more

Fuel Line

Fuel Line is the tube that allows fuel to travel from the fuel tank to the carburetor or injector.

Fuel Pump

An Electric Fuel Pumps from the fuel tank to the engine and is typically mounted on top of the fuel tank. A bad fuel pump can prevent the vehicle from starting.

Fuel Pump Shutoff

Fuel Pump Shutoff is a device that automatically shuts off the fuel pump after an accident.

Fuel Type

Fuel Type is used to power a vehicle. The most common type include electric, gasoline, diesel, ethanol, E85, biodiesel, natural gas.

Fuel/Water Separator

A Fuel/Water Separator refers to a device that separates the water from the fuel as part of the fuel filtration system.


Front-Wheel Drive (FWD) is a vehicle where only the front wheels are active. In such a system, the transmission is connected to the front wheels and not the rear wheels.

Gas Guzzler

Gas Guzzler is a federal tax for vehicles with high fuel consumption.


A Gauge found on the instrument cluster is a device used to display information such as fuel, speed, engine temperature, battery voltage, oil pressure, etc.

Gear Oil

Gear Oil is a heavy-duty lubricant specifically for gears within the differential case.

Gear Ratio

The number of revolutions made by a gear compared to the number of revolutions completed by the driven gear. Gear ratios are calculated by dividing output speed by input speed (i=Ws/W) or by… Read more


Gearboxes increase torque while reducing the speed of a prime mover output shaft (e.g., a motor crankshaft). This means that the output shaft of a gearbox rotates at a slower or higher rate than… Read more

Glow Light

Diesel engine pre-glow the cylinder chambers before the engine starts. The solid lights come on for a few seconds when the ignition is turned on. If the glowing light is flashing, it means there… Read more

Greenhouse Gases

Greenhouse gases absorb and emit radiant energy in the thermal infrared range. These gases are responsible for the greenhouse effect on planets.

Ground Clearance

Ground Clearance indicates the distance between the lowest point under the car and the ground.

Group Number

Group Number is a number established by the Battery Council International (BCI) that categorizes a battery based on its length, height, width, and terminal design. The ground number does not… Read more


Gross Vehicle Weight Rating, known as "GVWR." It is the total weight of a vehicle's curb weight, cargo weight capacity, and passenger weight.


Half-shaft is used to transmit power from the front (or rear) differential to a wheel.

Head Unit

Automotive head units, sometimes called infotainment systems, control various integrated information systems and entertainment functions via a unified hardware interface.


Headlight or Headlamp refers to a lamp attached to the front of a vehicle to illuminate the road ahead. Headlamps are also known as headlights, but in the most precise meaning, Headlamp refers to… Read more

Heads-Up Display

Heads-Up Display, or HUD, refers to any transparent display that delivers data without requiring the user to look away.

Heat Shield

Heat Shield refers to a device designed to minimize heat transfer that surrounds exhaust components. A heat shield protects an object from overheating by dissipating, reflecting, or simply… Read more

Heater Core

Heater Core refers to a radiator-like device used in heating the cabin of a vehicle. Hot coolant from the vehicle's engine passes through a winding core tube, a heat exchanger between coolant… Read more


Hesitation is a momentary loss of power during acceleration.

High Beam Indicator

High Beam Indicator refers to a light on your car's dashboard that stays on when your headlights are on. In most cars, it will be blue light.


Horsepower refers to a unit of measurement of power, or the rate at which work is done, usually about the output of engines or motors.


HVAC means Heating, Ventilation, and Air Conditioning. With a centralized HVAC system, both warm and cool air can be routed through the same ductwork and controlled by the same thermostat. When a… Read more


Hybrid vehicles combine the power of an electric motor and a gasoline or diesel engine.

Hydraulic Lifter

Hydraulic Lifters provide zero clearance when the engine is running, eliminating clatter and periodic adjustments. They do this by applying oil pressure against a spring-loaded plunger inside the… Read more


Hydrocarbons are organic chemical compounds containing only hydrogen and carbon atoms.

Idle speed

Idle Speed is described as when the RPM of the engine with no engine load. Engine speed when the gas pedal is not pressed while the engine is in a park or neutral.

Idler Pulley

Idler Pulleys transmit rotation from one shaft to another in applications where it is undesirable to connect them directly. Idler pulleys are also responsible for guiding and tensioning the engine… Read more

Ignition Coil

Induction coils in automobile ignition systems convert a battery's voltage into thousands of volts required to ignite fuel by creating an electric spark in the spark plugs.

Ignition Timing

Ignition Timing refers to the process of setting the time of a spark that will occur during the power stroke.


Insurance Institute for Highway Safety is a nonprofit U. S. organization funded by auto insurance companies that were established in 1959 and headquartered in Arlington, Virginia. Insurance… Read more


Low-Emission Vehicle is a vehicle that meets the super ultra-low emission vehicle ( SULEV ) standard for exhaust emissions and the federal inherently low-emission vehicle ( ILEV ) evaporative… Read more


Immobilizers are electronic security devices installed on cars that prevent the engine from starting unless the correct transponder key is present. It stops the car from being "hot wired… Read more

Independent Suspension

Independent suspension refers to any automobile suspension system that allows each wheel on the same axle to move vertically independently.

Induction System

Induction System refers to the following items: Carburetor or fuel injection system, intake ports, intake manifold, and intake valves.

Inline Engine

Inline Engines refer to a car engine where all the cylinders are straight rows instead of a V-shape.

Intake Manifold

Intake Manifolds, or Inlet Manifolds, supply the cylinders of an engine with fuel and air mixtures. The flow of air or air-fuel mixture from the throttle body to the cylinder head. The throttle… Read more

Intake Port

Intake Port is the passageway in a cylinder head that leads from the intake manifold to the intake valve.