The NHRA Index System is used to handicap cars running in the various NHRA classes. The index for each class is based on past and potential performance. Comparing the index for the two classes involved in a handicap race will provide the handicap difference for the start of the race.

Permanent index (CIC) adjustments at a given national and/or divisional event will be controlled with a scale that has two plateaus.

For example, from .61 through .649 under, the adjustments will continue to increase in .01 increments. However, from .65 to .709 under, the adjustments will be at a fixed plateau of .05. Then, from .71 through .749 under the scale will again increase in .01 increments. From .75 on the maximum cap will be fixed at a plateau of .10.

Example: 
.61 = -.01 
.62 = -.02 
.63 = -.03 
.64 = -.04 
.65, 66, 67, 68, 69, 70= -.05 
.71 = -.06 
.72 = -.07 
.73 = -.08 
.74 = -.09
.75 on = -.10

Permanent index (CIC) adjustments will only occur at national and divisional events and are not affected by the results of national open events.