A

A-arm	Suspension frame consisting of two radius rods joined in the shape of an A, for providing lateral location. A wishbone (UK). Also A-frame.
A-字臂	懸掛框架內的二把橫向位置的A字形狀定位臂。叉桿(英國)。見A字架。
A-frame	Structural frame in the shape of an A. A-shaped towing frame by which a truck is coupled to a drawbar trailer. Suspension frame in the shape of an A. See A-arm.
A-字框架	A字形狀的結構框架。 卡車連接掛鉤拖車的A字形狀拖行框架。 A字形狀的懸掛框架。見A字臂。
A-post	(A-pillar) Structural member forming the forward corner of the cab or passenger compartment. In structural analysis, the post may be assumed to include adjacent (contingent) parts of the door frame. See Figure B4
A-柱	(A-柱) 結構性組件形成駕駛室或客艙的前方角落。在結構性分析，這柱可被假定為包括門框的毗鄰(附帶)的部份。見圖B4。
ABS	See Anti-lock brake system; acrylonitrile-butadiene-styrene.
	見防抱死制動系統、丙烯睛丁二烯苯乙烯。
ABS relay valve	Electrically actuated pneumatic valve that controls the air pressure in the brakes of pneumatic anti-lock braking system during braking
ABS繼電器控制閥	利用電力開動的氣動閥，在剎車期間控制氣壓在有氣腔的防抱死制動系統。
absolute viscosity	See dynamic viscosity
絕對黏度	見動態黏度。
absorption	In acoustics, the reduction of noise by the application of a material that absorbs sound energy in the appropriate frequency range. See also cancellation
吸收	在聲學上，減少干擾是由於材料的應用在適當的頻率範圍吸收聲能。參見相消
accelerated hardening	Hardening, for instance of an adhesive, sealant, molded component, or finish, by the application of heat or catalytic action, or both.
加速硬化	運用熱力及催化作用的硬化，例如膠黏劑、密封膠、鑄造零件、或最後加工。
accelerated weathering test	Laboratory test on materials, components or complete vehicle that simulates the effects of weather on an accelerated time scale. See also salt spray test.
加速風化測試	模擬天氣的影響在一份加速的時間表內對材料、零件或完整車輛的實驗室試驗。參見鹽霧測試。
accelerator	Pedal by which the fuel flow to the engine is controlled, depression of the pedal causing the vehicle to accelerate.
油門	燃料流入引擎是受控於腳踏，腳踏的下降導致車輛的加速。
accelerator heel point	assumed point of contact of driver's heel with floor when foot is placed on the undepressed accelerator. Also AHP.
油門腳後跟點	當司機腳板放在沒有下降的腳踏上，腳後跟與地面的接觸假設點。
accelerator pump	Carburetion system that provides enrichment to offset mixture weakening when the throttle is opened rapidly on acceleration.
加速器泵	當加速時節流閥迅速地被打開，汽化系統提供添加去補償混合物變淡。
accumulator	Rechargeable electrical storage battery. (Obsolescent) A hydraulic accumulator for storing hydraulic pressure.
蓄電池、累加器	可再充電的電子蓄電池。(逐漸被廢棄) 水力累加器為存放液壓。
Ackermann steering	System of double-pivot steering in which two steered wheels pivot about a vertical axis and are steered by linked steering arms. The system was devised by Lankensperger but takes its name form the patent agent Ackermann. It was originally introduced to prevent capsizing of horsedrawn vehicles when turning sharply. See Figure A1. See also Jeantaud steering; reverse Ackermann
阿克曼轉向	雙樞軸轉向系統是由兩轉向車輪以一垂直軸為中心旋轉，轉向連桿使車輪同時被轉向。此系統由Lankensperger設計但代理人阿克曼卻用自己的名字為此專利命名。它最初被介紹是防止弄翻馬車當突然轉動。見圖A1。參見Jeantaud轉向、相反阿克曼。
acoustics impedance	Measure of the ability of a material to transmit sound. See also absorption
聲學阻抗	材料的傳送聲音能力單位。參見吸收。
acrylic	Of the unsaturated acrylic acid or its compounds. An acrylic resin based substance, such as a paint or adhesive.
丙烯酸酯	不飽和的丙烯酸酯酸或其化合物。 丙烯酸酯的樹脂根基的物質，例如油漆或膠黏劑。
acrylic resins	Resin based on acrylic acid, monomeric or polymeric, including methyl methacrylate, which range form fluid to solid. As molding materials noted for their transparency and used as an alternative to glass for curved canopies, also in colored or opaque sheet form, and as the basis of paints. Some formulations have high impact toughness.
丙烯酸酯樹脂	樹脂根據丙烯酸酯的酸，單體或聚合物, 包括甲醇異丁烯酸, 排列形式流體對固體。例如塑成的材料被注意到他們的透明度，被用作替代玻璃作為彎曲的頂篷，以及在有顏色的或不透明的板料形式作為油漆的根據。有些公式會使其有高衝擊韌性。
acrylonitrile-butadiene-styrene	Polymeric material used mainly in injection molding and extrusion, and in sheet form. Of good tensile and impact strength, and heat resistance. Also ABS.
丙烯睛丁二烯苯乙烯	聚合物材料被用於主要在注塑模型和擠壓，和以板料形式。有姿好拉伸、衝擊強度和熱抵抗。參見ABS。
active restraint	Occupant restraint system requiring manipulation by wearer, as for example a seat belt.
主動約束	佔有人約束系統要求穿戴者運用，例如安全帶。
acute toxicity	Toxic effect resulting from a a single exposure to a toxic substance. See chronic toxicity.
急性毒素	毒性作用起因於對一種毒性物質的唯一暴露。參見慢性毒力。
additive	A small amount of chemical substance added to improve the properties of a fluid such as a lubricant or fuel. See also detergent, dispersant.
添加劑	小量的化學物質增加而改進流體的特性，例如潤滑劑或燃料。參見洗滌劑、分散劑。
adhesion	Grip between road and tire, proportional to the static coefficient of friction. Joining of two surfaces by bonding using an intermediate agent called an adhesive. Measure of the strength of a bonded joint, as for example in peel or in tension.
附著力	路和輪胎之間的間隙，與摩擦靜態系數成比例。 使用一個中間媒介連接兩表面使結合，稱膠黏劑。 接合點強度的單位，例如在剝落中或在張力中。
adhesive	Material, usually in thixotropic or liquid form, for joining two surfaces by chemical or physical change or other process.
膠黏劑	一種材料，通常以觸變性或液體形式，為結合兩表面由化學製品或物理變動或其它過程。
adiabatic engine	Engine in which combustion heat loss to coolant is minimized. Also low heat rejection engine.
隔熱引擎	燃燒熱力流失對冷卻劑減到最小的引擎。
Admission stroke	See induction stroke
入場衝程	見進氣衝程。
adsorbent storage	Form of low-pressure storage of certain gaseous fuels, such as methane, through the adsorbent properties of activated carbon or other agencies. See also adsorption.
吸附的存貯	形成某些氣體燃料低壓存貯，例如甲烷，通過被激活的碳或其它媒介的吸附特性。參見吸收。
adsorber coated substrate	Adsorbent material, particularly one employed to temporarily trap emission gases prior to light-off of a catalytic converter.
吸附器覆蓋底層	吸附材料，特別使用於臨時活門板放射氣體在催化轉化器的點火之前。
Adsorption	Adhesion of a substance to a surface, as with some lubricant additives to metals. See also desorption.
吸附作用	一種物質對表面的黏附力, 和與一些對金屬的潤滑劑添加劑。參見解吸附作用。
advance stop	Mechanical contact to restrict ignition advance in vacuum advance system. See also retard stop.
預先停止	機械接觸去對限制燃點前進在真空前進系統。參見延遲停止。
advance ignition	Maladjustment of ignition timing in a spark-ignition engine whereby the spark occurs before its optimum setting.
預先燃點	在火花燃點引擎中燃點時間的失調，火花發生在它最佳設置之前。
aerial	(US: antenna) Wire or rod, often retractable, for receiving radio signals.
天線	(美國：antenna) 電線或棒，經常可收回的，接受無線電信號。
aerodynamic noise	Noise generated by the flow of air around and through a vehicle due to it forward motion, excluding noise of forced ventilation.
空氣噪聲	車輛前移時，空流圍繞和流過車輛所發生的噪聲，除了強制通風噪聲。
aerodynamic stability	Response of a moving vehicle to air perturbations such as gusts, side winds and disturbances form passing vehicles.
空氣穩定性	移動的車輛對空氣擾亂的反應，例如陣風、側風和車輛通過形成的干擾。
aerofoil	(US: airfoil) Streamlined planar shape such as wing intended to produce positive or negative lift or otherwise derive some effect from the flow of air. See also Gurney flap; wing.
風板	(美國：airfoil) 流線型的平面形狀，例如翼產生正或負的推力，或從空氣流動獲得某些作用。參見Gurney 襟翼、翼。
aerosol	Finely divided dispersion of a liquid or solid in a gas.
浮質	精巧地分開在氣體中分散的液體或固體。
afterburner	Device that completes the combustion of incompletely burned exhaust products within the exhaust system. See emission control.
後燃器	在排氣系統中把不完全地被燃燒的排氣物質完成燃燒的裝置。見排氣控制。
aftercooler	Heat exchanger that cools the induction air before it enters the cylinders of an engine, most often used in diesel engines downstream of a turbocharger. Often (and incorrectly) called an intercooler.
後冷卻機	冷卻空氣進入引擎的汽缸之前的熱轉換器，經常被使用在柴油引擎裡順流的渦輪增壓器。經常(和不正確地) 叫intercooler。
agglomerator	Separator or trap for removing water form fuel or oil. See also filter; sedimenter; separator
沈澱器	分隔器或捕捉在燃料或油中的水。參見過濾器、沈積器、分隔器。
aggregate body	Commercial vehicle truck body for the conveyance of aggregates, ballast and similar bulk materials, usually equipped with tipping gear.
聚集體 (俗稱：斗)	商用車卡車身為聚集體, 碎石和類似大量的材料搬運器, 通常被裝備以打翻齒輪。
agricultural commodity trailer	Off-highway trailer for conveyance of agricultural produce and bulk material.
農用商品掛車	非高速公路掛車為農業產物和大量材料搬運器。
agricultural tractor	On- and off-highway towing vehicle designed for the towing of agricultural equipment and trailers, and for general work on the land, and usually fitted with large-diameter wheels or a track laying system.
農用拖拉機	高速公路和非高速公路拖車被設計為拖曳農業設備和掛車, 和一般地面工作, 和通常符合大直徑車輪或軌道放置系統。
aiming	Adjustment of direction of beam of lamps to meet highway or legislative requirements.
瞄準	燈射線的方向的調整符合高速公路或立法要求。
aiming screws	Screws for adjusting the aiming of headlamps.
瞄準螺栓	頭燈瞄準的調整螺栓
air-assistaed hydraulic brake	Commercial vehicle braking system in which the master cylinder of a hydraulic braking system is actuated by pneumatic pressure or vacuum. Also air-over-hydraulic brake; vacuum-assisted hydraulic brake; vacuum-over-hydraulic brake.
氣體輔助液壓制動	液壓制動系統的主汽缸被氣動壓力或真空開動的商用車制動系統。見空氣液壓制動、真空輔助液壓制動、真空液壓制動。
air bag	Passive vehicle occupant restraint system in which on impact the rapid inflation of a cushion fitted in the fascia region restrains the body above torso level and prevents direct contact with the vehicle structure.
主動約束	衝擊減震墊在儀錶板區域迅速充氣，克制身體在軀幹水平之上，和防止與車輛結構直接接觸的被動車輛佔有人約束系統。
air bellows	Usually cylindrical or torose rubber vessel or sleeve which, when filled with a compressed gas or air, acts as a compression spring. Mainly used in commercial vehicle or trailer suspensions. See also air spring; air suspension; gas spring.
空氣風箱	通常用壓縮的氣體或空氣填裝，作為壓縮彈簧的圓柱形或腫脹的橡膠容器或套筒。主要使用在商用車輛或掛車懸掛。參見空氣彈簧、空氣懸掛宣揚懸浮、氣體彈簧。
air bleed passage	(UK:compensating jet) Jet or passage in a carburetor with a branch to atmosphere through which air is drawn and introduced into the fuel flow at high flow rates, thus preventing over-richness.
放氣通道	(英國：補償噴嘴) 於化油器的噴嘴或通道上，空氣被引入和以高流速的燃料流動被引進，有一分支與大氣貫穿，以防止在過度豐滿。
air-brake	Brake in which the force that actuates the brake mechanism is provided by compressed air acting on a diaphragm within a brake chamber or servo. Used mainly in commercial vehicle. Aerodynamic spoiler for retarding high-speed vehicles.
空氣制動	在制動室或伺服器之內，由壓縮空氣於膜片的作用力，開動制動機械裝置的制動。主要使用在商用車輛裡。 為高速車減速的空氣擾流器。
air cell	A small chamber, located in the cylinder head particularly of an indirect injection engine, in which combustion is initiated. The burning fuel charge passes through a throat to the main combustion chamber. Also swirl chamber. See also antechamber; Comet head; indirect injection; Lanova; pre-chamber.
空氣室	小室位於氣缸蓋特別在間接噴射引擎，燃燒的最先的地方。灼燒的燃料經過窄入口衝向主燃燒室。見漩渦室。參見前廳、彗星頭、間接噴射、Lanova、前室。
air cleaner	Any device such as a porous paper, wire mesh filter or oil bath cleaner, that prevents airborne particles form entering air-breathing machinery. Also air filter.
空氣除塵器	任何設備多孔紙、鐵絲網過濾器或油浴清潔器，防止氣載微粒進入空氣呼吸的機械。見空氣濾清器。
air compressor	Machine for delivering compressed air, as for example to an air brake system.
空氣壓縮機	給予壓縮空氣的機器，例如空氣制動系統。
air cooled	Cooled by the passage of air opposed to water, etc, Describes engines in which combustion heat is lost mainly through radiation and convection from finning. See Figure A2.
空氣冷卻	相對於水的空氣通道冷卻。引擎裡燃燒熱力主要通過發熱和對流的散熱板而流失。見圖A2 。
air dam	Aerodynamically shaped transverse extension of spoiler below front fender/bumper which reduces drag created by vehicle underbody. Also apron; underbumper apron. See also spoiler.
空氣屏障	橫向伸展的擾流器在前保險桿之下去減低由車底產生的空氣阻力。見擋板、保險桿下的擋板。參見擾流器。
air deflector	Contoured panel mounted on the roof of a commercial vehicle cab to improve air flow between cab and body.
空氣變流裝置	具輪廓的鑲板固定在商用車駕駛室的頂，改善氣流在駕駛室和身體之間。
air dryer	Device for removing moisture from air, but particularly from the compressed air of a commercial vehicle braking system.
空氣烘乾機	從空氣中除去濕氣的裝置，特別用於商用車輛制動系統的壓縮空氣。
air filter	See air cleaner. Air filter is the customary UK term.
空氣濾清器	見空氣除塵器。空氣濾清器是英國慣常術語。
air-fuel delivery ratio	Mass ratio of air to fuel inducted by an engine. The mixture strength. (Informal) See also stoichiometric ratio.
空氣燃料交付比率	由引擎引導空氣與燃料的質量比率。混合力（口語）。參見化學計量學的比率。
air horn	Audible warning device in which sound is produced by a blast of air through a reed or resonator. Engine induction tract leading from air filter or cleaner to a carburetor or inlet manifold.　(US informal)
空氣喇叭	由疾風通過簧片或諧振器產生聲音的可聽見的警告裝置。 引擎進氣的引導由空氣過濾器到或除塵器到化油器或進氣排歧管。（美國的口語）
air-injection	Addition of air stream under pressure, but particularly to an exhaust system to promote combustion of unburned hydrocarbons and conversion of carbon monoxide to carbon dioxide.
空氣噴射	在空氣流動壓力下，特別對於排氣系統促使未燒過的碳氫化合物的燃燒，和一氧化碳對二氧化碳的轉換。
air-lift axle	Pneumatically operated lifting axle of tandem axle commercial vehicle undercarriage. In some examples lifting or lowering are achieved by manipulation of pressure in the air bellows of an air suspension.
空氣舉升軸	雙聯驅動軌商用車輛底盤的氣動操作升降軸。在一些例子上，升或降是由空氣懸掛的空氣風箱壓力所操作的。
air-line	Pressure or vacuum-resisting tubing or piping for connecting the components of a pneumatically operated system.
空氣管線	連接氣動操作系統的零件的壓力或真空抵抗的管材或管道。
air-line connector	Plug and socket for making connections within a pneumatic system. See also gladhand; suzies.
空氣管線連接器	插座和插口在氣動系統內建立聯繫。參見耦合器、suzies。
air-management kit	Combined items for improving the aerodynamic efficiency of a vehicle, and particularly a truck, comprising for example air dam, air deflector and other devices.
空氣管理配套元件	結合改善車輛的空氣效能的元件，特別於卡車上，包括例如空氣屏障、空氣變流裝置和其它裝置。
air-over-hydraulic brake	Hydraulic brake system actuated by an air-hydraulic power unit, mainly used in commercial vehicles. Also air-assisted hydraulic brake.
空氣液壓制動	空氣液壓電源裝置開動液壓制動系統，主要被使用在商用車輛裡。並且由空氣輔助液壓制動。
air reservoir	Pressure vessel for retaining compressed air, particularly for the braking system of a heavy vehicle.
空氣庫	保留壓縮空氣的壓力容器，特別用於一輛重型車輛的制動系統。
air resistance	See drag.
空氣阻力	見阻力。
air seat	Pneumatically suspended driver or passenger seat, particularly as fitted to a commercial vehicle, military vehicle, or other vehicle where ride quality might otherwise be unacceptable.
空氣座位	氣動懸掛司機或乘客座位，特別適合於商用車輛、軍用車輛、或其它不能接受乘駕質量的車輛。
air shield	(US: air deflector) Flat or contoured plate normally extending vertically from the cab roof of a commercial vehicle or any vehicle towing a substantially taller trailer, to improve airflow. Also dragfoiler.
空氣檔板	(美國：空氣變流裝置) 平或具輪廓的板材通常垂直地延伸，從商用車輛的駕駛室頂或任何車輛拖曳極長的掛車以致改善氣流。
air shift PTO	Pneumatically engaged power take-off.
空氣轉變動力輸出	氣動轉合動力輸出。
air silencer	Device placed at the entry to induction system to attenuate the noise of induction.
空氣消音器	放置在進氣系統入口的設備，使進氣噪聲變弱。
air spring	Spring using the compressibility of air or other gas to react against the imposed load. See also air bellows; air suspension; gas spring.
空氣彈簧	彈簧使用空氣或其它氣體的壓縮性對抗強加的裝載。參見空氣風箱、空氣懸掛、氣體彈簧。
air strainer	An air filter or air cleaner. (US informal)
空氣過濾器	見空氣濾清器或空氣除塵器。（美國的口語）
air suspension	Vehicle suspension in which air in compression is the main or only spring medium. Also pneumatic suspension. See also air bellows; air spring; Hydragas; Moulton suspension.
空氣懸掛	壓縮空氣是主要或唯一彈簧媒介的車輛懸掛。見氣動懸掛。參見空氣風箱、空氣彈簧、液壓空氣、莫爾頓懸掛。
airless injection	Fuel injection by mechanical pressure only. The normal method of injection in a diesel engine. Also called solid injection.
不通風噴射	燃料噴射只靠機械的壓力。正常噴射方法在柴油引擎。參見固體噴射。
alcohol	Organic compound containing a hydroxile group, the basis of many synthetic solvents, and, of ethyl alcohol, and alternative fuel.
alternator	Alternating current electrical generator.
aliphatic	Hydrocarbon compund with open carbon chains rather than ring structure. See also aromatic.
alternative fuel	General term of any automotive fuel other than the prorietary pump fuels gasoline (petrol) and diesel fuel. See also alcohol; CNG; hydrogen; LPG; LNG.
aluminum	(UK: aluminium) Soft ductile element of high electrical conductivity. For engineering structural purposed it is used in alloy form, alloyed with copper, manganese, zinc, silicon and other elements depending on
aluminum	properties required. Reesistance to atmospheric corrosion varies with alloy composition. Extensively used in commercial and public service vehicle bodywork. Available in wrough and cast forms, and extrusions.
aluminum/air battery	Battery using aluminum anode and atmospheric oxygen cathode, the aluminum being converted to aluminum hydroxide in the process. The battery is not rechargeable.
ambulance	vehicle designed and manufactured specifically for conveying the sick, injured or disabled.
anaerobic	without air, in the sense of a process that takes place with the exclusion of air.
anaerobic adhesives	wide range of adhesives formulations, many of which are based on acrylics, which polymerise when oxygen is excluded. Applications include thread locking and locking of machine parts.
anchorage	Point of a vehicle structure to which a non-structural stress-carrying item is attached, as for example a seat belt, or seat.
anechoic	Not reflecting sound, but totally absorbing sound. Literally, giving no echo.
anechoic chamber	Acoustic test facility in which the inverse square law from a point source oof sound applies, and where there is silence if no sound source is generated within.
angle of lock	The horizontal angle between the plane of a steered wheel when cornering, and the plane when adjusted for straight ahead. See also lock.
angledozer	Bulldzer equipped with a blade set at an angle to vehicle's direction of motion so that spoil is discharged to one side while the vehicle is in steady motion.
Annoyance Index	A measure of acoustic annoyance, usually clculated as the sum of individual weighted noise parameters.
annulus	1. A ring-shaped components. 2. The annualar internally toothed wheel of an epicyclic (planetary) geartrain. See Figure P3
antechanmber	See also air cell; indirect injection; prechamber.
antenna	(UK: aerial) Wire or rod, often retractable, for receiving radio signals.
anthropometric dummy	Mannikin, or full-scale model representing the human form, for use in vehicle testing, such as impact testing, and ergonomic design.
anthropometry	Study of the measurement of the human body. See also ergonomics
anti-backfire valve	Valve that a1lows air to flow from an air-pump into induction manifold on deceleration to prevent backfiring.
anti-compounding valve	Valve in air brake circuit that prevent driver from applying air brakes and spring brakes simultaneously, and SO overloading the brake mechanism. Also called differential protection valve.
anti-dieseling valve	See overrun fuel cutoff.
anti-dive	Suspension geometry that reduces or prevent nose-down pitching on braking.
anti-jackknife system	Means of preventing a jackknife of an articulated vehicle, usually by locking the tractive unit and semi-trailer through the fifth-wheel coupling.
anti-knock	Counteracting a tendency to knock in an engine, as of fuel or combustion chamber design. anti-lacerative glass Glass that does not splinter on fracture and therefore diminishes the risk of laceration injury. See also safety glass.
anti-lock braking system	System that automatically controls wheel slip or prevents sustained whee1.locking on braking. widely called by acronym ABS(regrettably the same as that of polymer acrylonitrile butadiene styrene).
anti-lock braking system	Also anti-skid (informal); wheel slip brake control system. See also wheel speed sensor.
anti-lock modulator	Device that varies the braking force in accordance with the signal it receives.
Antiknock Index	Sepcification of the anti-knock properties of a gasoline fuel, particularly in North America where it is denned by half the sum of the Research Octane and Motor Octane Numbers.
anti-oxidant	Chemical that inhibits oxidation of materials with which it is in contact
anti-roll bar	Transverse torsion bar attached to a vehicle underside that couples the vertical displacements of nearside and offside wheels and in so doing reduces the vehicle's displacement in roll.
anti-roll bar	Use of tem roll-bar is discouraged as this often used in a different context. Also stabilizer-See also anti-sway bar. See Figure A.3
anti-run-on valve	Valve which prevents running on or “dieseling” of a spark ignition engine when the ignition is switched off.
anti-sail bar	Horizontal bar to restrain deflection in service of an anti-spray flap or mudflap.
anti-skid	See anti-lock braking system
anti-spin regulation	Control or prevention of wheelspin or wheelslip under power, normally by electronic sensing in conjunction with anti-lock braking. Also ASR
anti-spray flap	Flexible flap or curtain attached behind roadwheel to reduce road spray.
anti-squeal shims	Shims inserted between brake piston and backplate to reduce brake squeal.
anti-sway bar	Suspension member, particularly applied to beam axle rear suspensions, that limits vehicle body lateral movement or sway
anti-vibration mounting	Flexible mounting, as for an engine or other mechanical item, that reduces the transmission of noise and vibration from the mounted item to a structure such as a vehicle chassis
antifreeze	A chemical, such as ethylene gtyco1,added to the coo1ing water of an engine to depress the freezing point for winter operation
antipercolator	Tube and orifice in carburetor through which fuel vapor can escape from main jet tube to prevent over-enrichment due to vapor pressure.
apex seal	Combustion gas seal of the Wankel engine. See Figure w.l.
apparent viscosity	Viscosity of a liquid measured at a given shear rate for cases where viscosity is shear-rate dependent.
appliance	Specifically in automotive context, a fire fighting vehicle-Contracted from fire appliance.(Mainly UK usage)
approach angle	Maximum ramp angle that a vehicle can approach without fouling any pad of the vehicle. See Figure L.3
apron	Downward panel extension, usually transversely mounted at the front of a vehicle, to reduce drag resulting from disorderly flow under the vehicle. Also air dam; underbumper apron. See also spoiler.
Aquaplaning	(US: hydroplaning) Effect whereby a vehicle tire rides up on a thin surface of water and in so doing loses contact with the road surface resulting in sudden loss of traction and control.
aromatics	Unsaturated hydrocarbon additives containing at least one benzene ring, such as toluene, xylene and related hydrocarbons, which may be added, as appropriate, to fuel and lubricants. arrest marks See beach marks
artic	Articulated commercial vehicle tractor unit with semi-trailer. (UK informal) See Figure A4.
articulated bus	Usually single-decker bus with central articulation and accommodation for passengers in tractor and trailer units. See close-coupled city bus.
articulated vehicle	Vehicle consisting of two or more usually separable wheeled units, such as a towing vehicle, or tractor, and a semi-trailer. Articulation is primarily in the steering mode, though some degree of horizontal axis articulation will be necessary to enable
articulated vehicle	the vehicle to negotiate road surface irregularities. In offcial terminology usually a tractor and semi-trailer commercial vehicle combination with a small proportion of the trailer's load carried by the tractor.
articulated vehicle	Also a close-coupled city bus. See also articulated bus; drawing vehicle; truck; van.
aspect ratio	Ratio of length to width or, in the context of aerofoils, of span to average chord.
asperities	Microscopic projections from a surface that are significant in wear and lubrication.
Aspin engine	Four-stroke engine configuration incorporating a conical rotary valve, which is itself, part of the combustion chamber.
aspiration	breathing or induction process of an engine. Non-pressure-charged engines are often referred to as natural aspirated or normally aspirated.
ASR	See anti-spin regulation; traction control
Austin Martin linkage	Form of straight-line suspension linkage introduced by maker of that asymmetrical beam Light beam in which the light distribution is not symmetrical with respect to the median vertical plane of the beam.
atomization	Conversion of a liquid into a spray of very fine droplets.
Austin Hayes transmission	See Hayes transmission.
auto-ignition	Continued running of a spark ignition engine after the ignition has been switched off. Also dieseling; running-on.
auto transporter	Truck and trailer combination for conveying vehicles,usually in service of the motor trade.
autocar	1. A passenger car. (Archanic) 2. A passenger coach. (Contemporary French usage) See also charabanc.
autocycle	Light motorcycle with pedals for assisting the motor on starting and on inclines.(Obsolescent)The forerunner of the moped.
Autogas	Liquefied petroleum gas motor he1.Trade name in UK Also LPG.
ash	Non-combustible residue of a fuel after combustion.
autolube	Pressurized oil metering system on a dry-sump engine, such as that of a four-stroke motorcycle.
automatic	Vehicle with automatic transmission.(Informal)
automatic braking	Automatic brake application of a towed vchicle in the event of separation from the towing vehicle.
automatic choke	Thermostatically operated choke valve in carburetor inlet tract, closed when engine is cold and opening automatically as engine or induction air temperature rises.
automatic gearbox	(US: automatic transmission) Geared transmission unit in which gear ratios are automatically selected and engaged without the need for driver intervention. See also pre-selector. See Figure A5.
automatic leveling system	Suspension system that automatically adjusts front and rear ride heights to compensate for changes in axle load.
automatic slack adjuster	1. Device that automatically maintains the correct disposition of pushrod and cam lever in an air brake system. See also stack adjuster. 2. Any device that compensates automatically for slackness in a mechanical system.
automatic speed control	Device or system capable of maintaining selected vehicle speed in changing road conditions. See also cruise control.
automatic transmission	1.Transmission system or gearbox in which gear ratios are selected and engaged automatically, though usually with provision for the driver to manually override the selection.
automatic transmission	2.An automatic continuously variable transmission employing a variable-ratio friction drive such as a belt with expanding pulley. See also Hayes transmission; pre-selector; van Doorn transmission. See Figure A5.
automatic wear adjuster	Device that automatically compensates an actuating system for wear in the item being operated, such as a clutch or brakes.
automobile	(UK: passenger car) Self-propelled or motorized land vehicle, but particularly a private passenger car.
auxiliary brake	Any brake that serves in addition to the main braking system of a vehicle. See also engine brake; exhaust brake; retarder.
auxiliary driving lamp	Lamp intended to provide illumination forward of the vehicle and to supplement the upper beam of a standard headlamp system-See also fog lamp.
auxiliary gearbox	Gearbox used in conjunction with a main change-speed gearbox to provide an extra range of speeds, as for example by providing a 2:1reduction in addition to normal gearbox speeds.
auxiliary gearbox	Also auxiliary transmission.(Mainly US)See also range-change; splitter transmission.
auxiliary Iamps	An official term describing fog lamps and spot lamps of a vehicle.
auxiliary transmission	See auxiliary gearbox.
auxiliary venturi	See secondard venturi
average piston speed	See mean piston speed.
axle	Horizontal transverse shaft or beam with spindles on which road wheels are mounted. See also dead axle; fully floating axte; half shaft; live axle; stub-axle; transaxle. See Figure D5.
axle bearing	Any bearing that supports an axle or half shaft
axle camber	Wheel camber achieved in a beam dead axle by convex curvature of the axle.
axle carrier	See axle casing.
axle casing	(US: axle housing) Rigid non-rotating casing that carries an axle or half shaft.
axle chuckle	Noise emanating from rear live axle, usually due to excessive running clearances at the differential casing.
axle fore-and-aft shake	Longitudinal oscillatory motion of an axle
axle housing	See axle casing.
axle lift	Mechanism for raising and lowering a lifting axle of a commercial vehicle.
axle ratio	1. Overall ratio between engine revolutions and revolutions at driven wheels. 2. The final drive ratio
axle shaft	See axle
axle side shake	Lateral oscillatory motion of m axle
axle sleeve	Tubular casing of a live or dead axle shaft .See also axle casing.
axle spindle	Shaft machined to carry wheel bearings and seals and with means for securing the wheel to the axle.
axle spread	Longitudinal distance, or effective “wheelbase” between the axles of a tandem-or tri-axle suspension unit. See Figure T.1.
axle tramp	1. Form of wheel hop on live axles in which the left- and right-hand wheels hop in opposite phase. 2. Resonant oscillation of an axle/suspension system, usually due to wind-up of an insufficiently damped suspension during heavy acceleration.
axle tramp	The term is also used to describe a similar effect on vehicles without a beam axle.
axle weight	Static weight imposed on the highway by the wheels of one axle.
axle wind-down	Reversal of axle wind-up, effectively the rotation of the axle casing of a Hotchkiss type axle on braking or on going too suddenly into reverse. Often the term wind-up is used for both senses of rotation ,i.e.,for wind-up and wind-down. See Figure A.6.
axle wind-up	1. Torsional deflection of an axle shaft, as due to sudden application of power or brakes 2. Rotation of an axle casing due to flexure of semi-elliptical springs in reacting torsional loads.
axle wind-up	3. Oscillatory motion of an axle about the horizontal transverse axis through its center of gravity. See also axle tramp. See Figure A.6.