A term continental Europeans use to describe a convertible car. In the U.S. and England, the name Cabriolet is sometimes added to some automobile model lines to denote vehicles as having a folding soft (convertible) top.

Cabriolet is derived from the Italian verb capricolare "to jump in the air, " (latin capreolus = wild goat; cabrioler = jump like a goat). The term was often used to describe the movement of a French 18th century light, 2-wheeled, one-horse carriage with a folding leather hood, a large apron and known for its springy suspension as it would bounce with the horse's movements. Cabriolet coups were used widely in 19th century London as hired rides (taxis). When the taximeters were invented in the late 1800's they became known as Taximeter-Cabriolets, later shortened to Taxi Cabs.

Like the names of many carriages, cabriolet was adopted to vintage foldable-top automobiles, usually those produced in short numbers by popular designers. Cabriolet coups were hit their golden age in the 1930's but saw a revival after W.W.II with Cadillacs, Thunderbirds, Jaguar and Austin Healy. Today cabriolet coups of just about any make are particularly valuable and desirable.

An acronym for "Computer Aided Design". A computer design system which engineers and auto manufacturers use to speed engineering and development time. Some of the benefits of designing on a CAD system is engineers can view designs in 3D, and designs can be subjected to stresses and other simulated conditions on the computer to find potential weaknesses so design improvements can occur before construction.

Also, Cad is a shortened term used to describe a Cadillac.

See Corporate Average Fuel Economy (below).

A metal structure inside a bearing assembly that separates and spaces out the steel rollers or balls.

Also, short for Roll cage, a tube steel structure inside race cars and off-road vehicles which protects a driver in the event of a roll over.

The part of a disc brake system that forces the brake pads against the turning rotor to slow or stop a moving vehicle. When the driver applies the brakes, high pressure hydraulic pressure flows into the caliper and forces a piston (or pistons) toward the disc rotor. Brake pads are mounted in the caliper in front of the pads. The pads get forced against the disc rotor and create friction to slow or stop the moving vehicle. Brake calipers can have from one to four pistons.

A Calipers is also a precision measuring tool. An adjustable, sliding jaw on a ruler can be used to precisely measure diameters. A popular variation is the Dial Calipers, or Digital calipers which have a dial indicator that typically calibrated down to the .001 inch. Dial calipers are used by engineers and engine builders and are relatively accurate, however, their greatest advantage is speed and ease of use. If more accuracy is needed, a micrometer calipers is substituted. See Micrometer.

A shaft in an engine with numerous eccentric lobes ground onto it which open/close valves as it rotates. Often referred to as a "Cam". Camshafts typically rotate at 1/2 engine speed and are driven by a chain or belt which runs off the engine's crankshaft.

The camshaft is one of the most critical components of an engine because it controls valve timing and operation. One of the first moves an engine builder or performance specialist makes is swapping to a camshaft with taller lobes and longer valve duration. If a timing belt/chain skips or breaks, valve timing will be incorrect and engine damage could occur. For example, a valve might be pushed open when a piston reaches the top of it's travel. The result might be a bent valve.

A spark plug with reduced or no sparking capacity caused by a buildup of carbon on it's electrodes. The deposits appear black and fluffy and is generally the result of an overly rich air/fuel mix which might be caused by over-rich carburetion, too much choke (or sticking choke), a sticking manifold heat valve, or clogged air filter. The plug may be cleaned and reused.

A device used on gasoline engines which adds a metered amount of fuel to passing air to create a combustible air/fuel mixture -- which is then burned in the combustion chambers. The carburetor varies the amount of fuel injected into the air as a response to engine needs such as idling, acceleration, cruising, passing, etc.

Carburetors are no longer used on vehicles sold in the U.S. To meet increased federal fuel economy and emission standards, manufacturers switched over to fuel injection systems in the 1980's which allow for more precise control of air/fuel ratio.

A substance or condition which must be present for a chemical reaction to take place but is not permanently changed by the reaction itself.

Also, the name generally applied to the components inside a catalytic converter such as platinum, palladium, or rhodium that reduce the level of harmful pollutants in the exhaust. Also see Catalytic converter (below).

A device fitted to a vehicle's exhaust system that helps reduce air pollution. Catalytic converters are made of stainless steel and use a system of beads or honeycomb structure coated with platinum, palladium or rhodium as a catalyst to reduce oxides of nitrogen (NOx), and/or hydrocarbon (HC), and carbon monoxide (CO), and turn into less toxic gasses. Catalytic converters were adopted by U.S. auto manufacturers in the early 1970's to meet federal emission standards.

A salt-based chemical that is used for cleaning engine parts. Can be used for most metals except for aluminum.

A differential mounted in the transfer case of four-wheel-drive vehicles. Prevents axle wind-up and driveline binding by allowing speed differentiation between the front and rear driveshafts.

On a traditional four-wheel-drive vehicle without a center differential, turning results in the front and rear driveshafts spinning at different rates. Turning on dry surfaces, particularly pavement can lead to severe binding which my result in broken or damaged U-joints or axles in severe situations, or when larger-than-stock tires are used. But in slippery conditions when four-wheel-drive is most necessary, the wheels can slip a little. This is the reason most manufacturers of four-wheel-drive vehicles recommend that four-wheel-drive be engaged only in slippery conditions. Also see Four-wheel-drive.

A metric unit of linear measure. One centimeter equals .3937 of an inch. One inch equals 2.54 centimeters. The metric scale is based on the decimal system. The base unit of metric linear measure is the Meter (39.37 inches). Other metric valves:
Meter = 1
Millimeter (1/1000) - 1000 millimeters in a meter; 10mm = 1cm
Centimeter (1/100th) - 100 centimeter in a meter;1cm = 10mm
Decimeter (1/10th) - 10 decimeters in a meter; 1dm = 10cm
Kilometer (x1000) - 1000 meters in a kilometer (1 mile = 1.6km)

To add an electrical current to a battery, or restoring a battery's energy level. In an automobile, the vehicle's alternator provides a stream of current to keep the battery charged up. If a battery becomes drained, it can be charged up with an external battery charger.

Also - the mass of a single amount air/fuel mix that enters the combustion chamber of an engine during the intake stroke. Charging is also referred to adding refrigerant to a vehicle's air conditioning system.

An abbreviation for microchip (see Microchip)

A paint sample used by autobody technicians to determine the paint code of factory colors, paint variations, or custom mixes.

A small, missing flake of paint, or pock mark often caused by a rock or stone.

A friction device used to connect a driving member to a driven one. On a vehicle, a clutch commonly is located between the engine and transmission and helps to smoothly transfer engine power to the transmission (and the rest of the drivetrain). The common automotive clutch consists of a friction disc, pressure plate, throw-out bearing and a flywheel. When the clutch is slowly engaged the friction disc is allowed to slip. After many uses the friction disc wears and must be replaced. Replacement requires removing the transmission from the motor. Riding the clutch, or driving with a foot resting on the clutch can wear out a friction disc quickly.

A smaller, electrically operated clutch is used on air conditioning compressors to modulate refrigerant pressures. The clutch is engaged and the air-conditioner pump shaft pumps refrigerant when the air-conditioner is turned on, until a specified pressure has been met. Then a switch cuts current to the clutch which disengages the compressor and the pulley freewheels. When refrigerant pressure falls to a specified level, a pressure switch again sends current to the clutch which engages the compressor pump again and so on...

A rotating metal plate with friction material adhered (usually riveted) to it which is the primary wear component of the clutching mechanism. The clutch is splined at it's center and slides on the splines of the transmission input shaft. The disc is sandwiched between the engine flywheel and the pressure plate. In it's normal state, the clutch is held tightly against the flywheel (by the pressure plate) and turns with the motor, thereby turning the transmission input shaft. When the clutch pedal is pressed, a throwout bearing pushes releases pressure on the clutch disc and allows the clutch disc to spin freely of the engine. Therefore, the engine rotates but the clutch disc doesn't.

After a period of time and use, the clutch disc wears out and must be replaced which involves separating the engine and transmission.