Welcome Desk

Federal Tier 2 Standards

Starting in 2004, same set of emissions standards will be phased-in from 2004-2008, covering passenger cars, light trucks and large SUVs and passenger vehicles. The large SUVs and passenger vehicles will be classified under a new category – Medium Duty Passenger Vehicle (MDPV), HDT: Heavy Duty Truck, the least stringent for heavy trucks.

  • Tier 1: The former Federal (EPA) standard; carried over to model year 2004 in limited circumstances.
  • Tier 1-D: The former Federal diesel standard; carried over to model year 2004 in limited circumstances; permits higher NOx emissions than the Tier 1 standard.
  • Tier 2 bin 11: New Federal standard, applies only to MDPVs which will be deleted at the end of the phase-in period (2008).
  • Tier 2 bin 10: Least-clean Tier 2 bin applicable to cars with higher emissions values applicable to Heavy Light Duty Trucks (HDLT) and MDPVs which will be deleted at the end of the phase-in period (2006 for cars and 2008 for HDTSs and MDPVs).
  • Tier 2 bins 9 through 6: (Progressively cleaner standards). Bin 9 will be deleted before final phase-in of the Tier 2 program.
  • Tier 2 bin 5: “Average” of new Tier 2 standards. NOx emissions levels of all vehicles sold by each automaker must average to the bin 5 NOx level or cleaner when standards are fully phased in.
  • Tier 2 bins 4 through 2: (Progressively cleaner standards)
  • Tier 2 bin 1: The cleanest Federal Tier 2 standards. A zero-emission vehicle (ZEV).