CF
Co-efficient of friction: A convenient way of comparing the grip of tires from one to another. It is a measure of the ratio at which a tire converts downloading to traction.

CG
(Cg) Center of gravity: The point in space where the car`s mass is centered.

CHOP
Abruptly turning into a corner to prevent a pass.

COMMAND FLAG
Flag requiring action on the part of the driver.

COMPROMISE CORNERS
A corner where you compromise or modify your line to gain or benefit in another corner.

CONSTANT RADIUS CORNERS
Turns which can be measured with one arc starting at the turn-in point.

CONTACT PATCH
That part of a tire that’s in contact with the road at any one point in time.

CORNER ENTRY
The section of track between the brake point and where throttle application starts.

CORRECTION
The first phase in handling a slide (CPR) is the "Correction." The driver looks where he would like to go and turns the steering wheel toward the direction that rear of the car is sliding.

CPI
driver`s Safety Rating is derived from their Corners Per incident (CPI) average. Each track has a set number of corners. For example Lime Rock Park has seven corners. If you get one incident point every lap, your CPI would be seven. If you drove 100 laps, with only one incident, your CPI would be 700.

CPR
A skid-control technique involving the Correction, the Pause, and the Recovery.

CRAB/CRABBING
Gradually drifting toward the inside of the road and sacrificing radius on the approach to a corner. Crabbing is a symptom of low eyes and slow hand speed, and results in an early apex.