Adaptive cruise control
A driver-assistance system that maintains a set following distance from the vehicle ahead by adjusting speed automatically. Not self-driving. The driver still steers and stays responsible for the vehicle.
Reference glossary
The terms behind a precise vehicle answer.
60 plain-language definitions for the configuration, capability, efficiency and safety records used throughout this publication, organized alphabetically across 20 letter sections so a specific term is never more than a jump-link away. Each entry defines the word the way this site actually uses it: the same terms appear in vehicle records, trim guides, EPA family pages, ownership guides and the question library, so a definition here should read consistently wherever the term shows up elsewhere on the site. The glossary exists because words like "trim," "configuration" and "certified" carry specific, sometimes narrower meanings here than in everyday or marketing usage, and a reader who skips the definition can misread an otherwise accurate answer.
A
All-electric range
The distance a plug-in vehicle is rated to travel using stored battery energy before another energy source is required. Label manufacturer estimates separately from EPA ratings.
All-season tire
A tire designed as a year-round compromise between dry, wet, light-snow and tread-life performance. Winter traction is weaker than a dedicated winter tire's, by design.
All-wheel drive (AWD)
A drivetrain that can send power to all four wheels. Hardware, operating logic and whether it is standard or available vary by vehicle and trim.
Approach angle
The maximum incline a vehicle's front end can drive up without the front bumper or fascia striking the ground first. Larger angles generally mean better off-road ground clearance at the front.
Automatic emergency braking (AEB)
A system that applies the brakes on its own when it detects an imminent forward collision the driver has not responded to. Detection range and what triggers a response differ by brand and system.
Available
Offered on at least some configurations. Not standard. Not free. Not guaranteed without another trim, package or drivetrain.
B
Blind-spot monitoring
A system that warns the driver of a vehicle in an adjacent lane that is difficult to see with mirrors alone. A mirror check still matters; the system supplements it, not replaces it.
C
Carryover
A model year without a full redesign. Equipment, packages, pricing and calibrations can still change.
Certified pre-owned (CPO)
A used vehicle inspected and warrantied under a manufacturer- or dealer-run program, distinct from an ordinary used-vehicle sale. Checklist length and warranty terms differ by program. None of it is standardized industry-wide.
Continuously variable transmission (CVT)
A transmission that varies its gear ratio smoothly across a continuous range instead of shifting between a fixed number of gears. Driving feel differs from a traditional automatic or a dual-clutch transmission.
Curb weight
The weight of a vehicle with standard equipment and full fluids, but without passengers or cargo. Gross vehicle weight rating is a bigger, different number: it adds the maximum permitted occupant and cargo load.
D
DC fast charging
The fastest common public EV charging method, using direct current supplied by a dedicated station instead of the vehicle's onboard charger. Actual speed still depends on the vehicle's own maximum accepted rate, battery state and temperature, not the station's rating alone.
Departure angle
The maximum decline a vehicle's rear end can drive down without the rear bumper or fascia striking the ground first. Front and rear overhangs differ, so this gets measured separately from approach angle.
Destination charge
A manufacturer charge for transporting a new vehicle to the dealer. Generally separate from the advertised base MSRP.
Drivetrain
The components and layout that deliver power to the driven wheels, commonly described as FWD, RWD, AWD or 4WD.
Dual-clutch transmission (DCT)
An automated transmission using two separate clutches for odd and even gear sets, allowing near-instant shifts. Low-speed, stop-and-go behavior feels different from a torque-converter automatic.
E
EPA combined MPG
A weighted fuel-economy value derived from city and highway test results. Use the rating for the exact powertrain and drivetrain.
F
Forward collision warning
An alert that a collision with a vehicle or object ahead is imminent, based on the vehicle's own sensors. A warning only. Automatic braking needs a separate, paired system.
Four-wheel drive (4WD or 4x4)
A four-wheel-drive system generally associated with selectable modes or off-road capability. Not mechanically identical to every AWD system, despite the similar marketing language.
G
GCWR
Gross Combined Weight Rating: the maximum permitted combined weight of the loaded vehicle and loaded trailer, as specified by the manufacturer.
Generation
A major design cycle for a model. A new generation typically changes platform, body, powertrains or architecture enough that prior specifications should not be inherited.
Ground clearance
The vertical distance between the lowest point of a vehicle's underbody and the ground. A separate measurement from approach or departure angle, though all three shape off-road scraping risk.
GVWR
Gross Vehicle Weight Rating: the maximum permitted weight of the vehicle, occupants, cargo and accessories. It appears on the certification label.
H
Horsepower
A unit of engine or motor power output. A vehicle's peak horsepower figure may only be reached at a specific engine speed or under specific conditions, not across the entire operating range.
I
IIHS Top Safety Pick
An annual award from the Insurance Institute for Highway Safety for vehicles that meet its crashworthiness and, at the Pick+ level, front crash prevention criteria for that model year. Criteria change year to year, so an award from one model year does not carry forward automatically.
Infotainment
The combined in-vehicle system for audio, navigation, connectivity and vehicle information display. Screen size alone does not determine which features, subscriptions or phone-mirroring standards it supports.
Investigation
A formal NHTSA examination of a potential safety defect. Opening an investigation is not the same as finding a defect or announcing a recall.
K
Kilowatt-hour (kWh)
The unit used to state an EV or PHEV battery's total or usable energy capacity. A published battery-size figure may describe total pack capacity or usable capacity, which are not the same number.
L
Lane-keeping assist
A system that nudges steering or brakes individual wheels to help keep the vehicle within its lane markings. Lane-centering is different: a more active system that holds the vehicle near the center of the lane continuously, not just near the edge.
Level 1 / Level 2 charging
The two common home/public AC charging tiers: Level 1 uses a standard household outlet at the slowest rate, Level 2 uses a 240V circuit and dedicated equipment for meaningfully faster charging. Neither is the same as DC fast charging.
Limited-slip differential
A differential that transfers more power to the wheel with better traction when the other is slipping, instead of splitting power evenly regardless of grip. An electronically locking differential solves the same low-traction problem a different way.
M
Manufacturer communication
A document a manufacturer provides to dealers or others and submits to NHTSA, including some service bulletins. Not automatically a recall.
Model year
The manufacturer-assigned year used to identify a vehicle record. It may not match the calendar year when the vehicle was built or sold.
Monroney label
The federally required new-vehicle window label showing price, equipment, fuel-economy and other information for one specific vehicle.
MPGe
Miles per gallon equivalent: an energy-efficiency comparison used for electricity and other non-gasoline energy. Not the same as gasoline MPG.
MSRP
Manufacturer’s Suggested Retail Price. A base MSRP may exclude destination, options, taxes, registration and dealer charges.
N
Naturally aspirated
An engine that draws air in through normal atmospheric pressure alone, without a turbocharger or supercharger forcing in additional air. The baseline case forced-induction output claims usually get compared against.
NHTSA 5-Star Safety Rating
The federal government's crash-test rating program, scored per body style and, in current tests, separately for frontal, side and rollover scenarios before an overall score is derived. IIHS uses a different protocol and a different scale; the two ratings are not interchangeable.
O
Option package
A group of equipment selected together. A feature listed in a package is not standard on the trim unless the package itself is standard.
P
Payload
The weight available for occupants, cargo and accessories. A vehicle’s as-built payload is commonly shown on its certification or tire-and-loading label.
Plug-in hybrid (PHEV)
A vehicle with an externally chargeable battery and another propulsion source, usually a gasoline engine. Electric range and gas-mode efficiency are separate measures.
Powertrain warranty
The coverage period for major engine, transmission and driveline components, typically longer than a vehicle's basic bumper-to-bumper warranty. EV and PHEV battery coverage is commonly its own, separate warranty term.
R
Recall
A safety or compliance remedy campaign initiated by a manufacturer or required by NHTSA. Owners should check a specific VIN for unrepaired recalls.
Redesign
A major generational change. Dimensions, trim structures, powertrains and features from the preceding model should be reverified.
Refresh
A meaningful update within a generation, often involving styling, technology, powertrains or equipment. Also called a facelift or mid-cycle update.
Regenerative braking
A system that recovers some of a vehicle's kinetic energy back into the battery when slowing down, reducing wear on the friction brakes and extending range. Strength is often adjustable, and varies by vehicle, drive mode and battery state.
Roadside assistance
A manufacturer- or dealer-provided service covering towing, jump-starts, flat-tire and lockout help for a set coverage period. Usually tied to the new-vehicle warranty, not sold separately by default.
S
Standard equipment
Included on the stated configuration without selecting an additional option. The statement remains scoped to a year, market, body, powertrain and trim.
Supercharged
An engine with a mechanically driven forced-induction system that compresses intake air using power taken directly from the engine, instead of exhaust flow like a turbocharger. Power delivery feels different between the two, and the terms are not interchangeable.
System horsepower
A manufacturer’s combined output rating for an electrified powertrain. Not necessarily the arithmetic sum of the engine and motor peak ratings.
T
Technical service bulletin (TSB)
Manufacturer service information describing a condition, diagnostic path or repair procedure. A TSB is not automatically a recall or a free repair.
Torque
A measure of a powertrain's rotational twisting force, commonly cited alongside horsepower. Peak torque and peak horsepower often land at different engine or motor speeds, so neither figure alone describes how a vehicle feels across its full range.
Torque vectoring
A system that varies torque delivered to individual wheels, not just axles, to improve cornering or traction. Implementation differs by vehicle: some use braking, others a mechanical differential, and that choice changes how the system behaves.
Tow rating
The manufacturer’s maximum trailer-weight claim for a stated configuration and set of conditions. Payload, tongue weight, axle and combined-weight limits also apply.
Traction control
A system that reduces engine power or applies individual brakes to limit wheel spin under acceleration. Stability control is a different system. It intervenes during a skid, not at launch.
Trim
A marketed equipment position within a model lineup. The name alone does not guarantee the same equipment across years, bodies or powertrains.
Turbocharged
An engine with a forced-induction system that uses exhaust-gas flow to compress intake air, increasing output versus the same engine without it. Turbo lag, the delay before full boost arrives, varies by turbo size and tuning.
V
VIN
Vehicle Identification Number: the unique 17-character identifier used to resolve build details, safety campaigns and vehicle-specific records.
W
Wheelbase
The distance between the centers of the front and rear wheels. Longer wheelbases within the same model generally mean more rear-seat legroom. A separate measurement from overall vehicle length.