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4WD: Abbreviation of Four Wheel Drive.
4WS: Abbreviation of Four Wheel Steering.
Absorbed Glass Mat Battery: A type of lead acid battery where the electrolyte is absorbed in a matrix of glass fibres holding the electrolyte next to the lead plates.
Ackermann Steering: A double-pivoting steering system.
Active Suspension: A suspension that uses sensors to determine conditions and responds to these different conditions by making compensatory adjustments to the suspension.
Aerodynamic Drag: Resistance of a vehicle body to motion through the air. A smooth surface has less drag than a rough one.
Aerodynamic Noise: Sound generated by turbulent flow is just as if the field were generated by a distribution of quadrupole sources.
Aerodynamics: Lists all Aerodynamics topics in the Encyclopaedia
Aerodynamics Calculations: Lists all Aerodynamics Calculations in the Encyclopaedia
Aerodynamics Conversions: Lists all Aerodynamics Conversions in the Encyclopaedia
Aftermarket: All products and services used in the repair and maintenance of vehicles after the vehicle has been sold.
Air Filter: A device for removing impurities from the air.
Airbag: A bag that is inflated when an impact is detected to restrain a vehicle passenger.
All Terrain Vehicle: A vehicle used in rough surface conditions.
Alloy Wheel: A generic term used to describe any non-steel road wheel. The usual alloys are either aluminum or magnesium.
Alternator: An electric generator for producing alternating current.
Anti Dive Suspension: Front suspension kinematic characteristic which reduces the amount of pitch under braking forces.
Anti Lift Suspension: Rear suspension kinematic characteristic which reduces the amount of pitch under braking forces.
Anti Lock Brake System: A system that can modulate the brake pressure under hard braking conditions to avoid a brake locking and resultant skidding.
Anti Squat Suspension: Rear suspension kinematic characteristic which reduces the amount of pitch under acceleration.
Anti-Dive Suspension: The resistance to a vehicle's tendency to dip down in front when the brakes are applied.
Antifreeze: Compounds of glycol or alcohol, that lower the freezing point of cooling water systems.
Anti-Squat: A measure of a vehicle′s resistance to rear suspension squat due to weight transfer during acceleration.
Auto-Ignition Temperature: Minimum temperature at which the vapour/air mixture over a liquid spontaneously catches fire.
Automobile: A self-powered vehicle that travels on land typically with three or four wheels and with 2 to 9 seats.
AWD: Abbreviation of All Wheel Drive which also means Four Wheel Drive.
B100 Biodiesel: 100% biodiesel.
B20 Biodiesel: A blend of biodiesel fuel with petroleum-based diesel where 20% of the volume is biodiesel.
Baffle Plate: A metal plate that acts as a baffle.
Balance Pipe: A pipe connecting two points of a system to even out pressure fluctuations.
Ballast: Any liquid or solid weight placed in a vehicle to change the weight distribution or trim.
Berlin Eye: Refers to the eye of a leaf spring when the eye is upturned.
Biodiesel: Diesel fuel derived from renewable lipid feedstocks, such as vegetable oils and animal fats.
Biodiesel B100: 100% (neat) biodiesel. The mono alkyl esters of long chain fatty acids derived from renewable lipid feedstocks, such as vegetable oils and animal fats, diesel engines
Biodiesel B20: A blend of biodiesel fuel with petroleum-based diesel where 20% of the volume is biodiesel.
Blueprinted Engine: Ensuring the dimensions of the parts in the engine are more accurate and, therefore, closer to the original engine blueprint values.
Brake Bias: The distribution of braking between front and rear wheels.
Brake Disc Rotor: The rotating disc attached to the wheel axle and is clamped with brake pads to decelerate the vehicle.
Brake Graunch: The name given to the noise made by the brakes when they are just slipping when starting (or stopping) from rest. The brake graunch is mainly exhibited on the vehicles fitted with automatic transmission, but can also occur on manual vehicles e.g., on a steep hill. It is caused by brake pad stick-slip when static and dynamic friction is very similar. The term 'creep/groan' is also used to describe the brake graunch.
Brake Horse Power: This is the useful power available at the flywheel of an engine.
Brake Judder: Brake judder is the phenomenon where with medium to heavy braking from high speed, severe vibration is felt throughout the whole vehicle. It is often attributed to a mode of vibration in which the front suspension executes a predominantly fore and aft vibration with the two road wheels in-phase with each other. Excitation is often provided by the oscillatory forcing generated when applying the brakes to a brake disk that has disk thickness variation.
Brake Mean Effective Pressure: This is the average effective cylinder pressure that does useful work calculated from the brake horse power.
Brake Pipes: Pipes used to carry hydraulic brake fluid under pressure.
Brake Servo: A device which multiplies the driver′s physical effort in applying the brakes using the engine manifold vacuum.
Brake Specific Fuel Consumption: The ratio of the engine fuel consumption to the engine power output.
Brake Squeal: High frequency continuous tone when brakes are applied, this may be a single or multiple tones. The sound is generated by vibration on the surface of the disc itself.
Brakes: A device used to reduce the speed of a vehicle or object.
Bumper: An automobile bumper helps absorb the energy in an impact.
Camber Angle: Wheel angle relative to ground in front/rear view.
Carburetor: A device through which air and fuel are atomized and drawn into the engine.
Carburetor Choke: A temporary restriction in a carburetor throat that reduces the flow of air and enriches the fuel-air mixture to aid in starting the engine.
Caster Angle: The angle between upper and lower ball joints in side view, about which the wheel turns.
Chapman Strut: MacPherson strut used in a rear suspension.
Chassis: The mechanical parts of a vehicle attached to a structural frame, including axles, brakes, driveshafts, and suspension components.
Clutch: Coupling that connects or disconnects driving and driven parts of a driving mechanism.
Coachwork: The vehicle body - especially the comfort and luxury appointments as distinguished from the operational chassis.
Coil Over Shock: Standard assembly of spring and damper, where spring perches are at each end of damper.
Coil Spring: A steel spiral spring used to isolate a vehicle from the road.
Cold Cranking Amps: The current required by the starter motor to crank an engine in cold weather.
Compressed Natural Gas: Natural gas compressed to a volume and density that is practical as a portable fuel supply.
Compression Ignition: Ignition of a fuel charge by the heat of the air in a cylinder, generated by compression of the air, as in the diesel engine.
Compression Shackle: A short arm connecting the rear of the leaf spring to the frame which limits travel by compression.
Computer Aided Engineering: A technique for using computers to help with all phases of engineering design work.
Cone Clutch: The friction surfaces are on inner and outer cone surfaces.
Constant Velocity Joint: A special type of shaft coupling that allows the smooth transfer of power from an input shaft to an output shaft at all angles.
CV Joint: Abbreviation of Constant Velocity Joint.
Cylinder Head: The detachable part of the top of the cylinder block that seals the cylinder and forms the top of the combustion chamber.
Damper: Device used to reduce unwanted vibrations of a system.
Diesel Engine: An internal-combustion engine in which the fuel is injected into the cylinder near the end of the compression stroke and is ignited by the heat of the compressed air in the cylinder.
Diesel Particulate Filter: A device which physically captures diesel particulates preventing their discharge from the tailpipe.
Differential: Geared device between the driven wheels to allow varying rotational speeds of the wheels around corners.
Disc Brake: A type of brake in which two friction pads grip a steel disc that is attached to the wheel, with one pad on each side.
Disc Clutch: A disc on the end of the input shaft with a friction surface and a disc on the end of the output shaft.
Downturned Eye: Refers to the eye of a leaf spring when the spring turns down to form the eye.
Driveline: An assembly of one or more driveshafts with provisions for axial movement, which transmits torque and/or rotary motion at a fixed or varying angular relationship from one shaft to another.
Driveshaft: An assembly of one or two universal joints connected to a solid or tubular shaft member used to transmit rotational power.
Drivetrain: All of a vehicle′s components that create power and transmit it to the wheels, including the engine, transmission, differentials, and any interconnecting shafts.
Drum Brake: A brake that uses an enclosed rotating drum or can and stationary pads.
Electric Vehicle: A vehicle with one or more electric motors for propulsion.
Engine: A machine which produces power to do work, particularly one that converts heat into mechanical work.
Engine Bay: The enclosure in which an engine is installed in a vehicle.
Engine Configurations: Various configurations of engine have been developed over the years for power, low noise and vibration, economy or weight.
Engine Excitation Mechanisms: The physics behind the vibrations generated by the internal mechanisms of an internal combustion engine.
Engine Oil: Liquid that reduces friction or wear, or both, between the moving parts within an engine; removes heat, particularly from the underside of pistons; and serves as a combustion gas sealant for the piston rings.
Engine Orders: Engine orders are simply the amplitudes of the frequency components which are the multiples of the rotating frequency.
Engine Radiated Noise: Some empirical noise prediction models have been derived from a sample of 1m radiated engine noise measurements.
Engineering Design: Lists all Engineering Design topics in the Encyclopaedia
European Automobile Manufacturers Association: The Association des Constructeurs Europ�ens d�Automobiles and more often referred to by the abbreviation ACEA.
Eye Diameter: The inner diameter of the eyelet at each end of a leaf spring.
Flexible Fuel Vehicle: A vehicle that can be run on any blend of unleaded gasoline with up to 85 percent ethanol.
Flywheel: The wheel on the end of the crankshaft that gives the crankshaft momentum to carry the pistons through the compression stroke.
Foot Brake: Vehicle brake applied with the foot.
Fossil Fuel: A fuel such as coal, oil or natural gas that was formed through the decomposition of ancient plant and animal life.
Four Wheel Drive: All four wheels are driven by the engine.
Four Wheel Steering: A mechanism that allows the rear wheels to steer along with the front wheels.
Four-Stroke Engine: An engine operating on a cycle which is completed in four strokes, or two revolutions of the crankshaft.
Front Wheel Drive: A vehicle designed to have power applied to the front wheels.
Fuel Cell: A device that converts the chemical energy obtained from a redox reaction directly into electrical energy.
Fuel Consumption: Definitions of fuel consumption calculations.
Fuel Injector: Electro-mechanical device that precisely meters fuel into an internal combustion engine.
FWD: Front Wheel Drive - a vehicle designed to have power applied to the front wheels.
Gallon: This unit of volume is defined in the British and American system of units. Note 1 UK gallon = 1.2 US gallons.
Gearbox: A mechanical device that provides a torque-speed conversion between an input and output shaft.
Gross Vehicle Weight: The maximum loaded weight, including the vehicle itself, passengers, and cargo, for which a vehicle is designed and as specified by the manufacturer.
Handbrake: Vehicle brake that is applied by hand to hold the vehicle when stationary.
Heavy Duty Engine: An engine that is designed to allow operation continuously at or close to its peak output.
Hot-Stuck Piston Ring: A piston ring that is stuck when the piston and ring are at room temperature, and inspection shows that it was stuck during engine operation.
Hybrid Vehicle: A vehicle that combines a conventional propulsion system and a rechargeable energy storage system.
IC Engine: Any engine, either reciprocating or rotary, in which the fuel is consumed in the interior of the engine rather than outside of the engine.
Ignition Quality: The ability of a fuel to ignite when it is injected into the compressed-air charge in a diesel cylinder quantified by the cetane number.
Ignition Timing: The time of occurrence of ignition measured in degrees of crankshaft rotation relative to TDC (Top Dead Centre).
Inactive Length: The central portion of a leaf spring that is prevented from flexing by the U-plate.
Independent Suspension: A suspension system that allows each wheel on a vehicle to move up and down independently of the other wheels.
Institution of Electrical Engineers: The IEE is an innovative international organisation for electronics, electrical, manufacturing and IT professionals, with specifically tailored products, services and qualifications to meet the needs of today′s technology industry.
Internal Combustion Engine: Any engine, either reciprocating or rotary, in which the fuel is consumed in the interior of the engine rather than outside of the engine.
Joint Angle Limits: The limits, set in the input, on the driveline joint angles through the critical range, to control feasible driveline geometry.
Kingpin Angle: The angle of inclination from the vertical to the kingpin axis in the front view.
Kingpin Axis: The axis about which a road wheel is steered.
Kingpin Lower Point: The point of contact when you extend the kingpin axis to the ground.
Kingpin Offset: The offset from the centreline of the shock to the kingpin axis.
Kingpin Upper Point: The anchor point of the top of the shock absorber.
Limited Slip Differential: Differential with mechanism to limit the amount of differential speed between the two outputs.
Liquefied Natural Gas: Natural gas that has been refrigerated to cryonic temperatures where the gas condenses into a liquid.
Litre: A derived SI unit of volume.
litres per 100km: Unit of fuel consumption used in the automotive industry.
MacPherson Strut: Suspension system which uses a lower control arm and a damper/strut which is designed to take bending loads.
mile per gallon: Fuel consumption.
Module: The measurement that architects use to determine the proportions of a structure, for example, the diameter of a column.
Multiple Disc Clutch: Multiple plates on input and output shafts are brought together to transmit torque. The multiple plates increases the frictional area.
Naturally Aspirated: An engine that draws air in without the assistance of a supercharger or turbocharger.
Neutral Steering: Handling characteristic between understeer and oversteer.
Open Differential: Standard differential with no limited slip or torque sensing features, allows unlimited wheelspin.
Overdrive: A transmission ratio below 1:1.
Oversteer: The tendency of a vehicle to turn more than the apparent steering angle.
Petrol: A volatile, flammable liquid mixture of hydrocarbons, obtained from petroleum and used as a fuel for internal-combustion engines.
Petrol Engine: An internal-combustion engine in which the fuel is petrol that is drawn or injected into the cylinder along with air and ignited with an electric spark.
Petroleum: An oily, thick, flammable, usually dark coloured liquid that is a form of bitumen or a mixture of various hydrocarbons, occurring naturally in various parts of the world and often separated by distillation into petrol, naphtha, benzene, kerosene and paraffin.
Pre Ignition: Ignition of the mixture of fuel and air in the combustion chamber before the passage of the spark.
Propshaft: A driveshaft on a rear wheel drive vehicle that transfer rotational power from the engine-gearbox at the front to the differential at the rear.
Pushrod: A metal rod that transmits the motion of the camshaft to the valve actuators
Rear Wheel Drive: A vehicle designed to have power applied to the rear wheels.
RWD: Rear Wheel Drive - a vehicle designed to have power applied to the rear wheels.
Shock Absorber: A unit that adds damping to the relative motion of two parts.
Shunt: The transient response of the body to changes in the engine mean torque transmitted to the road wheel by the driveshafts.
Sleeve Valve Engine: In the sleeve valve engine the conventional valve train was replaced by a ported cylinder liner that was then rotated to align with ports in the block so as to achieve the timing for the intake and exhaust strokes for the four-stroke cycle.
Solid Axle: Suspension where left and right wheels are rigidly connected except torsionally.
Space Frame: A series of structural members assembled to create a skeletal system that supports the interior systems as well as the exterior skin and driveline components of a vehicle.
Spark Plug: Electrical device that fits into the cylinder head of an internal-combustion engine and ignites the gas by means of an electric spark.
Spark Plug Fouling: A deposit on the electrodes of a spark-plug of essentially non-conducting material that may, but will not necessarily, prevent the plug from operating.
Spark Plug Whiskering: A deposit of conductive material that tends to form a bridge between the spark-plug electrodes or to a ground, thus shorting out the plug.
Specific Fuel Consumption: The amount of fuel needed to provide a given power for a given period.
Spiral Wound Lead Acid Battery: Instead of having the electrodes as flat plates, the electrodes are rolled up in a spiral.
Splayed Springs: Leaf springs that are not parallel to the centreline of the vehicle in the plan view.
Spring Top Leaf Thickness: The thickness of the topmost leaf in a multiple-leaf spring.
Steering Offset: The distance from the point where the steering axis intersects the ground to the longitudinal line that runs through the centre of the tyre′s contact patch.
Sump: The engine oil reservoir.
Suspension: A system consisting of small particles dispersed in a liquid. The system of springs, links and absorbers that suspends a vehicle above its wheels.
Tension Shackle: A link attached to the rear eye of a leaf spring and to the frame of the vehicle.
Tie Bolt: A fastener which passes through the leaves of a leaf spring, holding it together.
Toe-In: Setting the front wheels to toe in will mean that when driven the wheels will tend to be aligned.
Toe-Out: Setting the front wheels of a front wheel drive car to toe out will mean that when driven the wheels will tend to be aligned.
Torque Converter: A fluid coupling used in automatic transmissions to transmit power from the engine to the wheels.
Torsion Bar: A type of spring that twists as it is compressed or stretched.
Transaxle: A transmission and differential combined in one integrated assembly.
Turning Circle: The diameter of the circular path created by the wheel furthest from the center of the turn.
Two-Stroke Engine: An internal-combustion engine that has one power stroke per revolution.
Tyre Aspect Ratio: The ratio of section height to section width multiplied by 100.
Tyre Tread Pattern: The design cut into a tyre surface to improve grip, particularly in wet conditions.
Universal Joint: A mechanical device which transmits torque and/or rotary motion between two shafts that are not in a straight line.
Upper Control Arm: The control arm that extends downward from the frame of the vehicle to connect with the axle.
V10 Engine: Ten-cylinder engine with the cylinders arranged in two banks of 5 and the shape of a V when looking along the line of the crankshaft.
V16 Engine: Sixteen-cylinder engine with the cylinders arranged in two banks of 8 and the shape of a V when looking along the line of the crankshaft.
V4 Engine: Four-cylinder engine with the cylinders arranged in two banks of 2 and the shape of a V when looking along the line of the crankshaft.
V6 Engine: Six-cylinder engine with the cylinders arranged in two banks of 3 and the shape of a V when looking along the line of the crankshaft.
V8 Engine: Eight-cylinder engine with the cylinders arranged in two banks of 4 and the shape of a V when looking along the line of the crankshaft.
Vacuum Pump: Device used for creating vacuums.
Valve Regulated Lead Acid Battery: A lead acid battery that uses pressure valves that open only under extreme conditions.
Vee Engine: One with two banks of in-line cylinders mounted with an angular separation on a common crankcase.
Vehicle: A means of transport, generally meaning an automobile.
Vehicle Noise: The noise produced by a land based vehicle that is radiated to the surrounding environment (exterior noise) or that is observed by the occupants of the vehicle (interior noise).
V Engine: One with two banks of in-line cylinders mounted with an angular separation on a common crankcase.
Viscosity Index: An arbitrary measure for the change of kinematic viscosity with temperature.
Viscous Coupled Differential: Limited slip device which uses sheared fluid between two plates to limit wheelspin.
VRLA Battery: Abbreviation for Valve Regulated Lead Acid Battery.
Watts Link: Lateral locating device for a solid axle.
Wheel: The Mesopotamians are credited with the invention of the wheel.
Wheelbase: The distance between the centres of the front and rear wheel axles as viewed from the side of the car.
Winchester Gallon: The US gallon, equivalent to 3.785411784 litres.
Zero-Offset Steering: A steering system whose geometry has a scrub radius of zero.