Notes: 

1.  Generally, effect dates of standards are for engines built on or after 1 January of the respective year, except where noted.      2.  All standards are based upon ISO 8178 C1 8-mode test for variable-speed engines and D2 5-mode test for constant-speed engines.  Transient test required beginning with 2011 phase-in.
3.  Separate NOx and HC standards separated by a "/".  Combined NOx and HC standards denoted in parenthesis "(  )". 
4.  Smoke requirements:  U.S: On-highway federal test procedure.  Europe - None, but some OEM's require R24.03 certification.  Japan has unique smoke standard and procedure.
5.  Generator sets in Europe are required to meet Stage II standards beginning 1 January 2007. 
6.  The U.S. on-highway consent decree includes a one year pull ahead to 2005 of the nonroad Tier 3 requirements for engines 300 - 749 hp.  Note slight power range discrepancy.
7.   For U.S.Tier 4, optional 0.30 g/kW-hr PM standard for engines 37-55kW in 2008.  Selecting this option allows a 1 year delay of Tier 4 Final implementation from 2012 to 2013.
8.  For U.S. Tier 4, "Split-family" standards are shown for 56 - 560kW.  Optional "Phase-in" standards for NOx are permitted by EPA.
9.  CANADA - MOU with Cummins requires Tier 1 engines built on or after 1 January 2000.  In 2004, Canada formally proposed to require EPA compliant engines beginning in 2006.
10.  KOREA - U.S. EPA Tier 1 and Tier 2 equivalent standards phased in beginning in 2004 and 2005 respectively for engines 19 - 560kW.  Vehicle certification rather than engine certification.

MOHREGS.XLS  Revised 02SEP04
Updated May, 2010