Automotive design terminology

A glossary of terms as relating to automotive design.

Some terms may be found at car body style.

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;1-box form: A categorization based on overall form design using rough rectangle volumes. In the case of the 1-box, it is a single continuous volume. Slight wedge formed front or rear are still generally placed in this category. e.g., Bus, original Ford Econoline.

;2-box form: A categorization based on overall form design using rough rectangle volumes. In the case of the 2-box form, there is usually a "box" representing a separate volume from the a-pillar forward and second box making up the rest. e.g., Station Wagon, Shooting-brake, Scion xB(2006)

;3-box form: A categorization based on overall form design using rough rectangle volumes. In the case of the 3-box form, there is usually a "box" representing a separate volume from the a-pillar forward. Second box makes up the "greenhouse". The third making up the c-pillar onward. e.g., Sedan

A

;A-line: The line running over the car, from headlight to taillight, tracing the car's silhouette.

;Axis-to-dash ratio: The critical relationship between front wheels and the windshield. The most notable differences can be seen between cars with front-engine, front-wheel drive layout and front mid-engine, rear-wheel drive layout: the former tend to have longer front overhangs with a smaller axis-to-dash ratios, while the latter have shorter front overhangs with much greater axis-to-dash ratios.

B

;Backlight: The rear glass window glass.

;Beltline: The line going from the hood which usually follows the bottom edge of the windows and continues to the trunk.

;Bling: (contemporary) See brightwork. May also refer to the strong use of jeweled lighting. Comes from the term bling-bling.

;Brightwork: Anything reflective added to a car to enhance appearance. May also be called chrome.

C

;Cab: Short for cabin. The enclosed compartment of a vehicle which contains the driver and passengers.

;Cab back: The cab of the vehicle is moved to the rear of the vehicle. Cars such as a 1970's Corvette could be considered cab back design.

;Cab forward: The cab of the vehicle is pushed forward. This design aesthetic was popular with Chrysler in the 1990s with the introduction of their LH platform cars.

;Character line: A line creased into the side of a car to give it visual interest. (interchangeable with swage line)

;Chrome: Brightwork using chrome plating.

;Cladding: Material (usually plastic) added to exterior of the car which isn't structurally necessary. May be functional to keep out dirt/debris as in underbody cladding, or may be cosmetic.

;Control Panel: Generally used in a Car/Truck for heating and cooling inside car environment according to the passenger requirements. Basically it is divided in to Different modes, Blower speed functions, AC, Temperature, Fresh recirculation of air. World wide control panel manufacturers are BHTC, Delphi, Visteon, Valeo, etc.

;Cowl: The base of the windshield.

D

;Daylight Opening (DLO): US DOT Term: For openings on the side of the vehicle, other than a door opening, the locus of all points where a horizontal line, perpendicular to the vehicle longitudinal centerline, is tangent to the periphery of the opening.:US DOT Term: For openings on the front and rear of the vehicle, other than a door opening, daylight opening means the locus of all points where a horizontal line, parallel to the vehicle longitudinal centerline is tangent to the periphery of the opening.

;Dead Cat Hole: The space between a car's tire and the wheel well. Currently there is a trend towards smaller dead cat holes.

;Deck: The horizontal surface at the rear of the car, which usually serves as the trunk lid.

;Droptop: A convertible.

F

;Fascia: The body-skin panel at the front of the car.

;Fender (wings, UK): Term for cowl covering the wheels of the vehicles. In more modern automobiles, this refers generally to the body panel or panels starting at the front "bumper" to the first door line excluding the engine hood. The opposite of the fender is the "quarter panel".

;Frame-on-rail: A design used in older (pre-unibody) cars, trucks, and SUVs. The power train and body are mounted to a rigid structural framework called a rail.

G

;Gill: A vent on the side of the fender that can be used as hot-air outlet, but usually decorative.

;Greenhouse: The glassed-in upper section of the car's body. Daylight Opening (DLO) in turn describes the actual window areas only.

H

;Header: The structural roof beam above the windshield.

;Hofmeister kink: BMW's trademark reverse-sweep kick at the bottom of last pillar window.

;HP (Hip Point or H-point): A conceptual plane parallel with ground that aligns to the vehicle passengers' hip/thigh join. This helps to describe the "seat" height of a vehicle design.

;Hood: (Bonnet in English speaking countries outside North America with the exception of the Canadian Maritimes) The engine cover on vehicles when the engine is located forward or aft of the passenger compartment.

I

;IP: Instrument Panel

The Dashboard is termed as Instrument Panel in Automotive Industries, sometimes this term is confused with the Instrument Cluster that is the group of speedometer, odometer and similar devices generally behind the steering wheel.

O

;Overhang: The distance which the car extends beyond the wheelbase. In car style design terms, this is the amount of body that is beyond the wheels or wheel arches.

P

;Plenum: The area at the base of the windshield where the wipers are parked.

;Pillar: A structural member that connects the roof to the body of the car. Pillars are usually notated from front to back alphabetically.:US DOT Term: Means any structure, excluding glazing and the vertical portion of door window frames, but including accompanying molding, attached components such as safety belt anchorages and coat hooks, that (1) supports either a roof or any other structure (such as a roll-bar) above the driver's head or (2) is located along a side edge of a window.

;Plug-in hybrid electric vehicle: A hybrid vehicle that can be plugged into the electric grid to recharge its battery to reduce gasoline usage. [See also [http://www.calcars.org/calcars-news/329.html "Hybrid Vehicles Gain Traction"] ]

;Powertrain: All the components that generate power and deliver it to the road surface.

Q

;Quarter-panel: (or rear quarter panel) refers to the panel at the back sides starting at the c-pillar, bordered by at top by the trunk (boot) lid and at bottom by the rear wheel arches ending at the rear bumper. This is the opposite of the fender.:Literally, the term originally referred to the rear quarter or the car's length.

R

;Rake: The tilt of a windshield. An extremely low or flat rake angle is considered to be "fast", as in fastback.

;Rocker: The body section below the base of the door openings sometimes called the "rocker panels".

;Scoop: Inset or protusion that implies the intake of air. May be functional for cooling/ventilation or purely ornamental.

;Shoulder line: The line or "shoulder" formed by the meeting of top and side surfaces extending from hood/fender shoulder to boot-lid/quarter-panel shoulder. The strongest example of this feature can be found on more modern of Volvo Cars.

;Sill line: Imaginary line drawn following the bottom edge of the greenhouse glass.

;Six line: A line extending from the C-pillar down and around the rear wheel well.

;Softtop: a convertible top which is made out of flexible materials like PVC or textile.

;Spoiler: A raised lip or wing which is used to 'spoil' unfavorable air movement across the body. Some designs are more functional than others.

;Staggered wheel fitment: The front and rear wheels are different widths. On sporty rear wheel drive cars, the rear tires are usually wider than the front.

;Strake: Crease in the sheet metal intended as a "speed line" styling feature.

;Swage line: Crease or curvature in the side of the body used to create visual drama. Sometimes the crease is functional and improves rigidity of the outer body. (interchangeable with character line)

T

;Track: The distance across the car between the base of the left and right wheels. (Like wheelbase, but side to side.)

;Truck: A typically large vehicle built using frame-on-rail construction consisting of a cab and a separate bed for cargo.

;Trunk: (Boot in UK) Compartment for storage of cargo which is separate from the cab.

;Tumblehome (tumble home): Generally refers to the way the sides of a car rounds inward toward the roof, specifically of the greenhouse above the beltline. This term is borrowed from nautical description of naval vessels.

;Turn under: The shape of the rocker panel as it curves inward at the lower edge.

V

;Valvetrain: The mechanisms and parts which control the operation of the valves.

W

;Wedge: Shape of the car as seen in the side profile. May be positive, negative or neutral. If the front is lower than the rear, then it is wedge-positive. If the rear is lower it is wedge-negative. If the car appears level from front to rear, then it is wedge neutral.

;Wheel arch: The visible opening in the side of a car allowing access to the wheel.

;Wheelbase: The distance front to back measured from where the front and rear wheels meet the ground.

;Wheel well (or bucket): The enclosure or space for the wheel.

;Windshield Trim: US DOT Term: Molding of any material between the windshield glazing and the exterior roof surface, including material that covers a part of either the windshield glazing or exterior roof surface.

;Wings: See Fender.

ee also

* Car body style
* Car classification

References