Its something with the amount of engines produced and how many of them meet tier II/III requirments. You can still produce non-EPA compliant engines so as long as you making less than XX% of your total engine production. Its like a 5 step process that if your not making the new EPA complient diesels(100% of the time) then you fall some grace period setup, that all pretty much ends in and around 2010.
Last edited by Sciulli : 06-22-2008 at 06:49 PM.