System Life means all phases of the system's development, production, or support.
Useful life means the relevant period of distance and/or time over which compliance with the relevant gaseous and particulate emission limits has to be assured.
Model Year means the CI engine manufacturer’s annual production period, which includes January 1st of a calendar year, or if the manufacturer has no annual production period, the calendar year.
Life-cycle cost means the expected total cost of ownership during the life of a product, including disposal costs.
Remaining Weighted Average Life on a given date with respect to any Equipment Note shall be the number of days equal to the quotient obtained by dividing (a) the sum of each of the products obtained by multiplying (i) the amount of each then remaining scheduled payment of principal of such Equipment Note by (ii) the number of days from and including such determination date to but excluding the date on which such payment of principal is scheduled to be made, by (b) the then outstanding principal amount of such Equipment Note.