Glossary of Automotive Terms

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  • Auto-Leveling Suspension: A system that automatically adjusts the vehicle's suspension to ensure that the rear remains level with the front, even when carrying heavy cargo. Some systems also offer various height settings for different driving conditions, such as off-road, normal, or high-speed driving.
  • Automated Manual Transmission: Known by various names, like "DSG" or "sequential manual gearbox," this type of transmission combines the control of a manual transmission with the convenience of automation. It uses electronic or hydraulic systems instead of a traditional clutch pedal and gear lever. The driver can choose between fully automatic mode or manually shifting gears.
  • B-Pillar: The vertical support post located between the front and rear doors of a vehicle, helping to provide structural stability
  • Balance Shaft Belt: A belt that connects a balance shaft to the engine's crankshaft, working in sync to reduce engine vibrations for smoother operation
  • Block Heater: An electric heater that warms the engine's coolant, making it easier to start the vehicle in extremely cold weather
  • Body Water Drains: Small openings in a vehicle's body designed to allow water to escape, preventing it from being trapped inside and causing damage
  • Bolstering: Cushions in a car seat designed to support and keep the driver or passenger securely positioned during driving
  • Brake Drying: A feature that reduces moisture on brake pads by lightly pressing them against the rotors without fully engaging, improving braking efficiency during wet conditions
  • Breakover Angle: The steepest angle a vehicle can drive over without getting stuck or hitting the ground between the front and rear wheels
  • Bumper-to-Bumper Warranty: A comprehensive warranty that covers most parts of the vehicle, excluding those that wear out during normal use, like tires, brake pads, and wiper blades. This warranty typically lasts for a certain number of years or miles, with exceptions for emissions-related components that are federally mandated to be covered for a minimum period.
  • Caliper Configuration: How many hydraulic pistons are in a brake caliper and how they are arranged to apply braking force
  • Cooling Fan and Shroud: A fan that pulls air through the radiator to cool the engine, with the shroud directing the airflow for better efficiency
  • CV Joints: Constant velocity joints are located on both ends of the drive axles, transmitting power while allowing for a full range of movement in the steering and suspension.
  • CVT (Continuously Variable Transmission): A type of transmission that doesn't have traditional gears but instead offers smooth, uninterrupted acceleration by constantly adjusting the drive ratio
  • Descent Control: A system used in off-road driving that automatically applies individual brakes to control the vehicle's speed on steep or uneven terrain, allowing a slow, controlled descent without the driver needing to use the brake pedal
  • Destination Charge: A fee added to the vehicle's price to cover the cost of delivering it from the factory to the dealership. This fee is standard regardless of the dealership's location, except in certain areas, like Alaska and Hawaii.
  • Drive Belt: A belt that transfers power from the engine to other components, like the alternator or water pump
  • Dual-Mode Hybrid: A hybrid vehicle that can operate in two modes: electric-only for lower speeds or gasoline-assisted for higher speeds and more power-demanding situations
  • Exhaust Pressure Regulator Valve: A valve that directs warm exhaust gases back into the engine to help fuel vaporize faster and reduce the time it takes for the engine to warm up
  • Extended Warranty: An optional warranty that extends the coverage beyond the vehicle's original basic warranty, covering repairs for a longer period or greater mileage
  • Four-Square Worksheet: A form used in car sales negotiations to track the key components of a deal: the vehicle price, trade-in value, down payment, and monthly payment
  • Four-Wheel Drive (4WD): A drivetrain system that distributes power to all four wheels of a vehicle, improving traction on difficult terrains.
  • Four-Wheel Steering: A feature where the rear wheels can also be steered, helping with cornering and improving stability at high speeds
  • Gross Vehicle Weight Rating (GVWR): The maximum allowable weight of a vehicle, including its own weight plus passengers and cargo
  • Heated Air Temperature Sensor: A sensor that measures the temperature of incoming air to help the vehicle's computer adjust engine performance
  • Horsepower: A unit of power that originally compared engine output to the work done by horses, now used to measure engine performance
  • Individual Monitors: Video screens installed in the rear seating area of a vehicle, often as part of an entertainment system
  • Instrumentation: The collection of gauges and displays that provide the driver with critical information about the vehicle's speed, engine performance, and other operational parameters
  • Keyless Ignition: A system that allows you to start the car without using a traditional key, typically by pressing a button that works when the key fob is inside the vehicle
  • Knee Airbags: Small airbags located below the dashboard that deploy in a crash to protect the knees and lower body
  • Lemon: A vehicle that turns out to have serious defects or issues that aren't obvious at the time of purchase. Informally, it refers to any problematic car. Legally, under various state "lemon laws," the buyer of a lemon has certain rights, such as the ability to return the car or get it repaired.
  • Li-Ion (Lithium-Ion) Battery: A rechargeable battery commonly used in electric vehicles that offers greater energy efficiency and lighter weight compared to older battery types, like NiCad or NiMH. However, Li-ion batteries are more sensitive to temperature changes and can be more fragile.
  • LNG (Liquefied Natural Gas): Natural gas that has been purified and cooled to a liquid state for easier storage and transportation. This process involves removing impurities such as water and heavy hydrocarbons and cooling the gas to around -260°F (-163°C).
  • LPG (Liquefied Petroleum Gas): A fuel blend primarily consisting of propane and butane, often used in vehicles or heating. An odorant, like ethanethiol, is added to help people detect leaks, since LPG is otherwise odorless.
  • Manifold Heat Control Valve: A temperature-sensitive valve that directs exhaust heat to the intake manifold, helping fuel to vaporize more quickly and reducing engine warm-up time
  • Memory Settings: A feature that allows drivers to save and recall preset positions for the car's adjustable features, such as seat, mirror, and steering wheel positions, with the touch of a button
  • Mid-Engine: A vehicle design where the engine is positioned between the driver and the rear axle, giving the car better weight distribution and handling
  • National Highway Traffic Safety Administration (NHTSA): A U.S. government agency responsible for vehicle safety regulations. It has the authority to investigate defects and order vehicle recalls if a design flaw poses a safety risk.
  • Navigation System: A GPS-based device that uses satellite signals to locate a vehicle's position and guide the driver to a destination using digital maps
  • NOx (Nitrogen Oxides): A group of harmful gases produced during high-temperature combustion in engines, which contribute to air pollution and smog when they react with other chemicals in sunlight
  • Office of Defects Investigation: A branch of the NHTSA that investigates reported vehicle defects, manages safety recalls, and ensures that manufacturers conduct adequate recall campaigns
  • On-Board Diagnostic System (OBD): A vehicle's computer system that monitors the performance of various components and alerts the driver to malfunctions through warning lights, such as the "check engine" light. It also stores trouble codes that can be read by technicians to diagnose problems.
  • Oversteer: A handling condition where a vehicle turns more sharply than intended because the rear tires lose traction, causing the back of the car to swing out
  • Oxygen Sensor: A sensor in the exhaust system of a vehicle that measures the air-fuel mixture and sends this information to the engine's control unit, helping to optimize fuel efficiency and reduce emissions
  • Parking Sensors: Small sensors embedded in a vehicle's bumpers that detect nearby objects and warn the driver, typically through beeps or visual alerts, to help avoid collisions while parking
  • Payload: The maximum amount of weight a vehicle can carry, including both passengers and cargo, calculated as the gross vehicle weight rating (GVWR) minus the vehicle's empty weight
  • PCV Valve/PCV Filter: Part of the positive crankcase ventilation (PCV) system that helps reduce emissions by rerouting combustion gases from the engine crankcase back into the intake system for burning instead of releasing them into the atmosphere
  • Post-Collision Communication: A safety feature in telematics systems that automatically contacts emergency services after an accident, providing the vehicle's location and alerting authorities
  • Power-Activated Release: A mechanism that electronically opens a vehicle's trunk or hatch, as opposed to older manual systems that use cables or levers
  • Power Train Warranty: A warranty that covers the key components responsible for moving the vehicle, such as the engine, transmission, and driveshaft, excluding consumable parts like belts or hoses
  • Purge Valve: A valve in the evaporative emissions control system that releases fuel vapors from the charcoal canister into the engine's intake to be burned, preventing the canister from becoming overloaded with vapors
  • Radiator Core and AC Condenser: The heart of the vehicle's cooling and air conditioning systems, consisting of thin tubes and fins that allow air to pass through and dissipate heat from the engine and AC system
  • Rear Spoiler: An aerodynamic feature attached to the rear of a vehicle to reduce lift and improve stability at higher speeds by manipulating the airflow over and under the car
  • Recall: A notification from a vehicle manufacturer alerting owners to a serious defect that affects the vehicle's safety. Dealers are required to fix affected vehicles free of charge.
  • Regenerative Braking: A technology used in hybrid and electric vehicles where the motor switches to generator mode during braking, converting kinetic energy into electrical energy to recharge the battery
  • Salvage Title: A special title issued to a vehicle that has been declared a total loss due to significant damage, typically exceeding 70% of its pre-accident value. These vehicles are often sold at auction and may be repaired or rebuilt.
  • Seat Belt Pretensioners: A safety feature that tightens the seat belt during a collision to hold the occupant securely in place before the airbags deploy
  • Secondary Air Supply System: A system that reduces vehicle emissions by introducing fresh air into the exhaust stream to promote further combustion of any unburned hydrocarbons
  • Self-Leveling Headlights: Headlights that automatically adjust their angle based on the vehicle's suspension height to ensure optimal illumination and prevent blinding oncoming drivers
  • Shiftable Automatic Transmission: A type of automatic transmission that allows the driver to manually shift gears when desired, offering more control over the driving experience
  • Skid Plate: A protective shield located under the vehicle to guard the engine and other vital parts from damage when driving over rough or uneven terrain
  • Stability Control: Also known as electronic stability control (ESC), this system helps prevent skidding by adjusting the brake pressure and, in some cases, reducing engine power to keep the vehicle on its intended path.
  • Technical Service Bulletin (TSB): A notice issued by a vehicle manufacturer about specific problems known to affect certain models. Unlike a recall, repairs under a TSB are usually made only if the issue is verified by a technician.
  • Thermostatically Controlled Air Cleaner: A component in older carbureted engines that directs warm air into the carburetor during cold starts, helping the engine reach optimal operating temperature faster and reducing emissions
  • Tire Prefix: A letter code on a tire that indicates its intended use, such as "P" for passenger vehicles or "LT" for light trucks
  • Traction Control: A safety system that prevents wheel spin by regulating engine power or applying brakes to specific wheels, ensuring better traction and stability on slippery or uneven surfaces
  • U-Joints (Universal Joints): Flexible joints found in the drivetrain that allow the drive shaft to transmit power while accommodating movement in different directions
  • Understeer: A condition where the vehicle does not turn as sharply as the driver intends because the front tires lose traction and slide outward
  • Underwriting: The process used by insurance companies to evaluate risk, determine whether to issue a policy, and decide the premium rates based on that risk assessment
  • Variable Gear Ratio Steering Assembly: A steering system that changes the steering response based on the speed of the vehicle, allowing for easier steering at low speeds and more precision at higher speeds
  • Variable Valve Timing: A feature in engines that adjusts the timing, lift, or duration of the engine's valves during operation to improve performance, fuel efficiency, and emissions control
  • Wheel Alignment: The process of adjusting the angles of the wheels to meet specifications for optimal handling, tire wear, and safety
  • Wheel Speed Sensor Wiring: Electrical connections that send information from each wheel to the vehicle's computer, helping systems like anti-lock brakes and traction control adjust to improve safety
  • Wideband Oxygen Sensor: A more advanced type of oxygen sensor that allows the engine's control unit to make quicker and more precise adjustments to the air-fuel mixture for better performance and emissions control
  • ZEV (Zero Emission Vehicle): A vehicle that produces no exhaust emissions during operation, such as electric or hydrogen-powered cars, meeting the most stringent emissions standards

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