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OC

Oxidation Catalyst.

OCC

Output circuit check.

Occupational Safety And Health Administration (OSHA)

A branch of the Federal Government that regulates and oversees the occupational environment as related to health and safety.

Occupational Safety Glasses

Protective eye wear designed with special hit-impact lenses, frames, and side protection.

OCIL

Overdrive cancel indicator light.

OCP

Over crank protection.

OCS

Overdrive cancel switch.

Octane

A gasoline's ability to resist detonation. The higher the octane number, the greater the fuel's resistance to detonation.

Octane Enhancer

Common term designating components that are added to gasoline to increase octane and reduce engine knock. Examples are toluene, ethanol, ETBE, and MTBE.

Octane Number

The number representing the average blend of iso-octane with an index of 100, and other hydrocarbons with an index of 0, usually between 87 and 92.

Octane Rating

A term used for octane number.

Octane Requirement

The minimum octane rating of a fuel required to operate an engine without a spark knock.

Octane Requirement Increase

(ORI) The increase in octane requirement that results from the build up of combustion chamber deposits.

Odd Fire

A V-6 engine with a 60- or 90-degree block having a conventional crankshaft with two connecting rods attached to each of three journals that produces uneven firing.

Odometer

A mechanical or electronic counter in the speedometer that indicates trip or total miles accumulated on the vehicle.

OE

Original equipment.

OEM

An abbreviation for original equipment manufacturer.

Off Highway

A term used for off-road.

Off Pavement