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COC

Conventional oxidizing catalyst

Cockpit

The driver's compartment of a vehicle.

Code Installation

In general, an installation that conforms to the state and federal regulations and codes to insure safe and efficient conditions.

Code Of Federal Regulations

Regulations that are generated, published and enforced by the United /states government.

COE

An acronym for cab over engine.

Coefficient

1. Any of the factors of a product considered in relation to a specific factor; a constant factor of a term as distinguished from a variable; 2. A number that serves as a measure of some property of characteristic.

Coefficient Of Drag

Abbreviated Cd. This is an aerodynamic term applied to a vehicle's shape, which is used to measure the vehicle's ability to pass through air. A lower coefficient of drag typically translates into increased performance and stability on the road, not to mention lower fuel consumption. As an example, a flat plate has a Cd of 1.25. The ideal shape, a teardrop, is rated at .03 Cd.

Coefficient Of Drag (Cx)

A measure of the air resistance of a moving vehicle; a measure of how much air is moved as the vehicle moves from one point to another.

Coefficient Of Friction

The measure of the resistance of one surface moving against another. It is obtained by dividing the force required to slide the surfaces across one another by the pressure holding the surfaces together.

Coefficient Of Water/oil Distribution

The ratio of the solubility of a chemical in water compared to its solubility in oil.

Cog

A gear, particularly the final drive gear.

Coil

[1] A term often used to describe a suspension spring or the component that is formed when several turns of wire are wound on a cylindrical form or on a metal core.

Coil

A part of a vehicle's ignition system that boosts the low voltage output from the battery to the high voltage output required by the spark plug in order to ignite the air and fuel mixture in the combustion chamber. Some vehicles use only one coil, but many late-model vehicles feature one coil per cylinder. A high-output coil is designed to improve the performance and fuel economy of an engine by helping it to burn the air and fuel mixture more completely.

Coil Bind

A condition where springs are compressed to the point that the coils touch.

Coil Failure

1. A defective ignition coil. 2. Also see coil spring failures.

Coil Over Shock

A suspension component that consists of a shock absorber inside a coil spring.

Coil Spring

A spring-steel bar or rod that is wound into the shape of a coil to provide an up-down springing effect. Found on most vehicle suspensions, these springs are used to support the car's weight, maintain height, and correctly position all other suspension parts, but are little help in supporting side-to-side or lateral movement.

Coil Spring

A spring made from wire that has been wound into a spiral shape. Coil springs are used in the suspension of many vehicles (see coil spring IFS), as well as in the valvetrain of pushrod engines. Each coil spring will have a particular rate, which traditionally is expressed in lb./in. In other words, a spring with a rate of 100 lb./in. requires 100 pounds of force to compress it 1 inch. The higher a spring’s rate, the stiffer the spring. When an engine has been modified to make substantially more power, it often is necessary to install a set of stiffer valvesprings to control the valves. In a suspension, a stiffer spring provides more control, greater load-carrying abilities and improved handling, but also a harsher ride. A softer spring essentially does the opposite. A nice compromise between the two is provided by a progressive-rate coil spring.

Coil Spring Ifs

Short for coil spring independent front suspension. A vehicle’s front suspension that allows each wheel to move independently of the other, and that uses coil springs and shock absorbers to control up-and-down movement.

Coil Spring Solid 4-bar

A front suspension design used on several pickup trucks and SUVs, including new Jeep Cherokees and the 1994-2000 4-wheel-drive Dodge Ram. This design also is used front and rear on some vehicles, such as the 1997-2000 Jeep Wrangler TJ and 1998-2000 Jeep Grand Cherokee. Lift kits for this style of suspension typically include taller coil springs and drop brackets for the link bars, or they may entail a swap to longer bars. Some milder lift kits will use a set of coil spring spacers.