Deterioration factor
Deterioration factor means the difference between exhaust emissions at the end of useful life and exhaust emissions at the low hour test point expressed as either: the ratio of exhaust emissions at the end of useful life to exhaust emissions at the low hour test point (for multiplicative deterioration factors); or the difference between exhaust emissions at the end of useful life and exhaust emissions at the low hour test point (for additive deterioration factors).
Source
40 CFR § 94.2
Scoping language
The definitions of this section apply to this subpart. They also apply to all subparts of this part, except where noted otherwise.