ABS
A system that regulates braking to reduce wheel lockup during braking.
Reviewed 05.10.2026wheel.news
Automotive glossary
Understand the concepts used in our guides and calculators. Documented definitions, examples, and related reading.
60 concepts
AC Charging
Charging in which the alternating-current supply is converted inside the vehicle to direct current to charge the battery.
Reviewed 05.10.2026Advanced driver assistance systems (ADAS)
A group of advanced systems that assist the driver through warnings or interventions in vehicle functions.
Reviewed 05.10.2026All-wheel drive
A configuration in which the powertrain can transmit motion to the wheels on both axles.
Reviewed 05.10.2026Annual equivalent rate (TAE)
The annual equivalent rate is an annual indicator of the effective cost of financing, calculated using the interest and the costs that must be included. In Spain, it is identified as TAE.
Reviewed 05.10.2026Aquaplaning
A loss of effective tire contact with the road when a layer of water prevents the tire from making normal contact with the surface.
Reviewed 05.10.2026Automatic emergency braking
A function that may apply the brakes automatically when it detects a situation consistent with a likely collision.
Reviewed 05.10.2026Battery Electric Vehicle (BEV)
A vehicle propelled by electric motors powered by a battery that can be recharged from an external source.
Reviewed 05.10.2026Battery state of health (SoH)
An indicator of a battery’s condition relative to a reference and according to an assessment method.
Reviewed 05.10.2026Beam
Beam is a measurement of a vessel’s width. It is commonly given as the maximum width under a specified measurement definition.
Reviewed 05.10.2026Boat displacement
Displacement is the mass of water displaced by a floating boat, and is equal to the boat’s mass in that condition.
Reviewed 05.10.2026Boat length
Boat length is a longitudinal measurement of a vessel. The definition used must be stated, for example overall length or hull length.
Reviewed 05.10.2026Braking distance
The distance a vehicle travels from the start of braking until it stops.
Reviewed 05.10.2026Charging curve
A representation of how charging power changes during a charging session or across the state of charge.
Reviewed 05.10.2026Clutch
A component that connects and disconnects the transfer of motion between the engine and the gearbox.
Reviewed 05.10.2026Compression ratio
The ratio of the cylinder’s maximum volume to its minimum volume during piston movement.
Reviewed 05.10.2026DC Charging
Charging in which external equipment supplies direct current to the vehicle’s battery system.
Reviewed 05.10.2026Depreciation
Depreciation is the loss in a vehicle’s value over time and through use. It represents the difference between its initial value and the value it retains at a later date.
Reviewed 05.10.2026Differential
A transmission mechanism that allows the wheels on a driven axle to rotate at different speeds.
Reviewed 05.10.2026Direct injection
A system in which fuel is introduced directly into the engine’s combustion chamber.
Reviewed 05.10.2026Draft
A boat’s draft is the vertical distance between the waterline and the lowest submerged reference point of the boat, according to the definition being used.
Reviewed 05.10.2026Electronic stability control (ESC)
A system that compares the vehicle’s movement with the requested trajectory and intervenes to help restore stability.
Reviewed 05.10.2026Energy consumption
The amount of energy a vehicle uses to travel a distance or operate over a period, expressed relative to that distance or period.
Reviewed 05.10.2026Engine displacement
The total volume swept by the pistons between their extreme positions inside the engine cylinders.
Reviewed 05.10.2026Fast Charging
A term used for higher-power charging, usually associated with direct-current equipment.
Reviewed 05.10.2026Fuel Cell Electric Vehicle (FCEV)
An electric vehicle that generates electricity for propulsion using a fuel cell, typically powered by hydrogen.
Reviewed 05.10.2026Gearbox
A transmission assembly that makes it possible to use different ratios between the rotation of the engine and that of the driven wheels.
Reviewed 05.10.2026Hybrid Electric Vehicle (HEV)
A vehicle that combines a combustion engine with one or more electric motors and does not allow its traction battery to be recharged externally.
Reviewed 05.10.2026Indicated airspeed
Indicated airspeed is the speed reading shown by the airspeed indicator before applying any applicable instrument or installation corrections. It is commonly identified as IAS.
Reviewed 05.10.2026ISOFIX
An anchorage system for connecting a compatible child restraint system to specific points in a vehicle.
Reviewed 05.10.2026Kilowatt (kW)
A unit of power equal to one thousand watts. It expresses the rate at which energy is transferred or transformed.
Reviewed 05.10.2026Kilowatt-hour (kWh)
A unit of energy corresponding to maintaining a power of one kilowatt for one hour.
Reviewed 05.10.2026Knot
A knot is a unit of speed equal to one nautical mile per hour, or 1.852 kilometers per hour.
Reviewed 05.10.2026Lift
Lift is the component of aerodynamic force perpendicular to the relative airflow. In an airplane, it helps support the airplane’s weight during flight.
Reviewed 05.10.2026Loan amortization
Loan amortization is the repayment of borrowed principal. A periodic installment may include both principal repayment and interest.
Reviewed 05.10.2026Mass in running order
Mass in running order describes the mass of a vehicle prepared for driving, including the items specified by the applicable definition. It is not necessarily the same as its unladen mass or a particular measured mass.
Reviewed 05.10.2026Maximum authorized mass
Maximum authorized mass is the greatest mass at which a vehicle may be driven under its authorization. Spanish vehicle documentation commonly uses the abbreviation MMA.
Reviewed 05.10.2026Maximum takeoff mass
Maximum takeoff mass is the maximum mass limit authorized for an aircraft when beginning takeoff under the conditions of its certification. It is commonly shown as MTOM or MTOW in technical documentation.
Reviewed 05.10.2026Mechanical horsepower (hp)
An Anglo-American unit of power equal to approximately 745.7 watts under its mechanical definition.
Reviewed 05.10.2026Metric horsepower (CV/PS)
A metric unit of power equal to approximately 735.5 watts.
Reviewed 05.10.2026Mild Hybrid Electric Vehicle (MHEV)
A hybrid system in which the electric component assists the combustion engine without independently providing electric propulsion for the vehicle.
Reviewed 05.10.2026Nautical mile
The international nautical mile is a unit of length equal to 1,852 meters. It is used especially in maritime and air navigation.
Reviewed 05.10.2026Nominal interest rate
The nominal interest rate is the interest agreed for a loan over a period. In Spain, it is commonly identified by the acronym TIN.
Reviewed 05.10.2026Payload
Payload is the mass available for occupants and cargo within the vehicle’s authorized mass limit, according to the definition and figures in its documentation.
Reviewed 05.10.2026Plug-in Hybrid Electric Vehicle (PHEV)
A vehicle that combines electric and combustion propulsion and allows its battery to be recharged from an external source.
Reviewed 05.10.2026Pressure altitude
Pressure altitude is the altitude corresponding to an atmospheric pressure referenced to the standard atmosphere. It is a pressure reference, not a direct measurement of distance above the ground.
Reviewed 05.10.2026Preventive maintenance
Preventive maintenance comprises scheduled inspections and actions intended to keep a vehicle functioning and reduce the likelihood of failures.
Reviewed 05.10.2026Range
The distance a vehicle can travel with the energy or fuel available under specified conditions.
Reviewed 05.10.2026Regenerative Braking
The recovery of some of the energy of motion by an electric machine acting as a generator during deceleration.
Reviewed 05.10.2026Residual value
Residual value is the estimated value a vehicle will retain at the end of a specified period or contract.
Reviewed 05.10.2026Service interval
A service interval is the time, distance, or condition reference that determines when a maintenance action is due under the vehicle’s maintenance plan.
Reviewed 05.10.2026State of charge (SoC)
An indicator of the charge available in a battery relative to the capacity reference used by its management system.
Reviewed 05.10.2026Torque
A quantity describing the turning action produced by an engine, usually expressed in newton-metres.
Reviewed 05.10.2026Total cost of ownership
Total cost of ownership brings together the costs of acquiring, financing, using, and maintaining a vehicle over a defined period, taking into account the value it retains at the end.
Reviewed 05.10.2026Towable mass
Towable mass is the mass limit for a trailer that a vehicle is authorized or technically capable of towing, according to the applicable documentation.
Reviewed 05.10.2026Turbocharger
A device that uses a turbine driven by exhaust gases to power an intake-air compressor.
Reviewed 05.10.2026Usable battery capacity
The amount of energy the system allows to be used from the battery within its operating limits.
Reviewed 05.10.2026Vehicle axle
In a vehicle description, an axle identifies a set of wheels positioned along a transverse reference line. Depending on the design, it may be a steering axle, a driven axle, or serve other functions.
Reviewed 05.10.2026Wheelbase
Wheelbase is the longitudinal distance between a vehicle’s reference axles. In a two-axle car, it is measured between the front and rear axles.
Reviewed 05.10.2026WLTP
A harmonized test procedure for obtaining consumption, emissions, and, depending on the vehicle, range data under defined conditions.
Reviewed 05.10.2026