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Displaying 251 - 300 of 502 glossary terms Use the search function to find terms.
Intake Stroke

Intake Stroke is the first stroke where the piston moves downwards from the top dead center creating a vacuum and sucking in the air-fuel mixture in the cylinder.

Intake Valve

Intake Valve allows the fuel-air mixture to suck inside the cylinder for the first stroke.


Intercooler refers to a heat exchanger that cools the air that has been heated during compression. This application is in Turbo - or Supercharged applications.


Intermittent is when a problem or error comes and goes with no obvious observations or warnings.

Internal Combustion Engine

Internal Combustion Engine refers to which the air-fuel mixture gets burned.

Jack Stands

Jack Stand is a secure holding device that secures heavy loads once lifted by a floor jack. These are usually rated for a maximum lifting capacity (for example, 1.5 tons or 3 tons).

Jump Start

Jump Start is used if the car's battery is discharged and a charged battery or device gets connected to help start the vehicle by supplying the necessary amps.

Keyless ignition

Keyless Ignition is the push-start ignition in most modern cars. The key fob gives an electronic sensor signal that indicates the vehicle to its identification.


A kickdown in an automatic transmission is referred to as a downshift by a strongly pressed throttle (gas pedal).


Kilometers are metric units of measurement and equal one thousand meters.

Knee airbags

Knee Airbag is a device installed usually on the driver's side beside the steering column to deploy in a case of impact to protect the driver's legs.

Knock Sensor

Knock Sensor measures the high frequency and vibrations caused by detonations by the engine. It is mounted on the engine and is computerized.


KPH stands for Kilometers per Hour. Kilometers per hour are units of speed, indicating the distance traveled in an hour.

Lane Departure Warning System

Lane Departure Warning Systems alert drivers if their vehicle leaves its lane.

Lane Watch

Lane Watch is a camera that will show the blind spot on the right side of the vehicle. The blind spot can be seen on the monitor of the vehicle.

Lateral Acceleration

Sideways acceleration during cornering. Centrifugal force acts on the car and tries to pull it outward to counteract this outward force that the tires have to have an equal and opposite force to… Read more

Leaf Spring

Leaf Springs consists of a long, slender length of spring steel with a rectangular cross-section. Leaf Springs can either be attached directly to both ends of the frame or directly at one end,… Read more


Lemon is a vehicle that has numerous or severe defects apparent before its purchase. There is a lemon law that provides owners with certain rights.


Lessee refers to a person that signs a lease for a vehicle. The Lessee is responsible for the car and the vehicle's payment.


LEV stands for Low Emission Vehicle. A low-emission vehicle emits relatively low levels of motor vehicle emissions.


A lithium-ion battery or Li-ion battery (abbreviated as LIB) is a type of rechargeable battery. The batteries have a high energy density, no memory effect (other than LFP cells), and low self-… Read more

Limited warranty

Limited Warranty is the indicated warranty by the manufacturer, usually measured in time and or mileage.

Limited-Slip Differential

Limited-Slip Differential (LSD) allows its output shafts to spin at different speeds but limits the maximum difference between the two shafts. A lithium-ion battery or Li-ion battery (abbreviated… Read more

Live Axle

Live Axles are beam axles in which the shaft (or, more commonly, several shafts connected as one) also transmits power to the wheels. Contrary, a beam axle that does not transmit power is called a… Read more


Liquefied Natural Gas (LNG) is natural gas predominantly methane, CH4, with some mixture of ethane, C2H6 that cooled down to liquid form for ease and safety of non-pressurized storage or transport… Read more

Lock Cylinder

Lock Cylinder is when a car can be locked or unlocked by operating a mechanical mechanism.

Locking Differential

Locking Differential "locks" both wheels on a shaft together as if on a shaft, overcoming the main limitation of a standard open differential. It will force both wheels to turn in unison… Read more

Low Voltage

Low Voltage is when the alternator is not charging correctly in a vehicle. A battery sign will illuminate your dashboard that indicates a charging failure. A red battery sign will show in your… Read more


Liquid Petroleum Gas (LPG), or Liquefied Petroleum Gas (LPG), is a mixture of hydrocarbon gases commonly used for heating, cooking, and motor vehicles.

Lug Nut

Lug Nuts lock the wheels on the car. These nuts are locked inside the wheel hub.

Luggage Capacity

Luggage Capacity is the volume measurement of the vehicle's cargo trunk.

Lumbar Support

Lumbar Support is a part of a vehicle's seat that supports the back of the driver or passenger. The adjustable lumbar mechanisms allow the user to change the seatback shape to make it more… Read more

MAF Sensor

A Mass (Air) Flow Sensor (MAF) measures the flow rate of air entering an internal combustion engine. The Engine Control Unit (ECU) must know how much air is in the engine to balance and deliver… Read more

Main Bearings

Main Bearings hold the crankshaft in place and allow it to spin in the engine block. Main bearings are plain bearings or journal bearings held in place by the engine block and bearing caps.


Maintenance refers to the periodic preventive care of the vehicle. Maintenance has to be followed according to the owner's manual to void the manufacturer's warranty.

Manual transmission

Manual Transmission uses a clutch and manual gear shifter to change the gears within the transmission.

Mass Air Flow Sensor

A Mass (Air) Flow Sensor (MAF) measures the flow rate of air entering an internal combustion engine. The Engine Control Unit (ECU) must know how much air is in the engine to balance and deliver… Read more

Master Cylinder

The brake master Cylinder acts like a hydraulic pump that is attached to the pedal. It moves and detaches the brake fluid to the… Read more

Maximum Cargo Capacity

Maximum Cargo Capacity refers to the maximum volume and weight that includes the rear seats folded if applicable.

Memory Settings

Memory Setting refers to a presetting that remains constant in the ECM unless disconnected from a power source. (I.E., the mirrors, seats, radio, and HVAC systems).

Metric Sockets

Metric Socket is a tool that attaches to a socket wrench, ratchet, torque wrench, or another turning tool to tighten or loosen a fastener such as a nut or a bolt. Drive Hole indicates the size of… Read more


Malfunction Indicator Lamp (MIL) refers to a warning light on the instrument cluster that indicates a malfunction. This warning light indicates almost anything from a loose gas cap to a serious… Read more

Mileage Allowance

Mileage Allowance is the number of miles permitted to drive in the term of the lease. Exceeding those can lead to penalties or increased contract costs.


Misfire is the failure of igniting the air-fuel mix completely. It can cause by several things.


Mount holds a power train or accessories to a vehicle's chassis or body.


Miles Per Gallon (MPG) refers to the miles driven dived by the fuel consumed.


Miles Per Hour refers to the speed at the vehicle is traveling at the moment.


Manufacturer's Suggested Retail Price (MSRP), also known as "sticker price," is the suggested retail price of a product at which the manufacturer recommends that the retailer sell… Read more


Muffler refers to the last part installed of the vehicle's exhaust system. It is a chambered muffler that reduces the noise created by the exhaust.

Multi-Point Injection

A Multi-Point Injection system uses a fuel injector for each cylinder.