TERMS

A term numerically indicating the relative

antiknock value of a gasoline. For octane

numbers 100 or below, it is based upon a

comparison with the reference fuels isooctane

(100 octane number) and n-heptane (0 octane

number). The octane number of an unknown

fuel is the percent by volume of isooctane with

n-heptane which matches the unknown fuel in

knocking tendencies under a specified set of

conditions. Above 100, the octane number of a

fuel is based on the engine rating, in terms of

milliliters of tetraethyllead in isooctane which

matches that of the unknown fuel.

Organization Economic Cooperation and

Development

Original Equipment Manufacturer

One of the shallow grooves cut into the rubbing

faces of a bearing shell to improve the

distribution of oil over the shaft and bearings.

The grooves are connected with an oil supply

hole or cup and act like ducts in conveying the

oil to the various parts of the bearings.

1. A loose ring, the inner surface of which rides

a shaft or journal causing the ring to rotate. The

ring dips into the reservoir of lubricant, from

which it carries the lubricant to the top of the

shaft for distribution to a bearing. 2. This is the

ring on an internal-combustion engine piston

controls the lubrication of the piston and cylinder

walls, as contrasted to the compression ring.

1. That characteristic of a liquid which is

responsible for the degree of friction between

two surfaces which cannot be accounted for on

the basis of viscosity alone. 2 The ability of a

lubricating oil to orient itself on bearing surfaces

so as to form new surfaces with a low coefficient

of static friction.

Oil Labeling Assessment Program

Octane Requirement Increase