The definitions in subpart A of this part apply to this subpart. The following definitions also apply to this subpart:

Averaging means the exchange of emission credits between engine families within a given manufacturer's product line.

Banking means the retention of emission credits by the manufacturer generating the emission credits or obtaining such credits through trading, for use in future model year averaging or trading as permitted in this part.

Emission credits represent the amount of emission reduction or exceedance, by an engine family, below or above the applicable HC + NOX (NMHC + NOX) emission standard, respectively. FELs below the standard create “positive credits,” while FELs above the standard create “negative credits.” In addition, “projected credits” refer to emission credits based on the projected applicable production volume of the engine family. “Reserved credits” are emission credits generated within a model year waiting to be reported to EPA at the end of the model year. “Actual credits” refer to emission credits based on actual applicable production volume as contained in the end-of-year reports submitted to EPA. Some or all of these credits may be revoked if EPA review of the end-of-year reports or any subsequent audit action(s) reveals problems or errors of any nature with credit computations.

Trading means the exchange of emission credits between manufacturers.