May 1997—EPA established the framework necessary for a voluntary program that would make significantly cleaner burning new cars available nationwide. The EPA has been working to forge an agreement between the Northeastern states and the automobile manufacturers to produce National Low Emission Vehicles. Although the Northeastern states and auto manufacturers still must agree to the program, the rule sets out enforceable provisions such as emission standards and test procedures that would apply if such an agreement is reached. EPA will continue to work with the parties to complete this program.

Under the program, auto manufacturers would have the option of agreeing to comply with tighter tailpipe emission standards—standards that EPA does not have authority to impose now. Once manufacturers committed to the program, the standards would be enforceable—just as all other federal motor vehicle standards are enforceable. Manufacturers have indicated that they are willing to volunteer to meet these tighter standards because EPA and the states in the northeastern part of the country (the Ozone Transport Region or OTR States) have indicated that they are willing to agree to a program that provides manufacturers with regulatory stability, that recognizes that establishing advanced technology vehicles in the northeast is a shared responsibility (rather than the sole responsibility of auto manufacturers), and that reduces regulatory burden by harmonizing federal and California motor vehicle standards. EPA believes that National LEV is an enforceable program that will achieve reductions in new motor vehicle emissions that are at least equivalent to the reductions that would be achieved through OTC (Ozone Transport Commission for the OTR) state-by-state adoption of a LEV program.

Section 202 of the Clean Air Act establishes the standards which apply to motor vehicles sold in the 49 states. The 1990 amendments to the Act established more stringent tailpipe emission standards, referred to as the Tier I standards, which apply to light duty vehicles and light-duty trucks. The implementation of those standards is in phases, beginning with the 1994 model year. The discussions regarding a LEV equivalent program which, through consensus of the affected parties, would establish standards more stringent than Tier 1 standards, have focused on the development of an approach based on the nationwide sale of vehicles identical to vehicles certified under CAL LEV standards as LEV category vehicles.

The CAL LEV program established five categories of vehicles: California "Tier 1" vehicles, transitional low emission vehicles (TLEVs), low emission vehicles (LEVs), ultra-low emission vehicles (ULEVs), and zero-emission vehicles (ZEVs), each category having increasingly stringent hydrocarbon emission standards. The CAL LEV standards for LEV category vehicles are .075 grams per mile (gpm) NMOG, 3.4 gpm carbon monoxide (CO), and 0.2 gpm oxides of nitrogen (NOx). Beginning in the year 2001, the National LEV program will require on average all new cars and light-duty trucks sold outside California to meet the California Low Emission Vehicle (LEV) standard. Prior to the nationwide introduction of this vehicle, auto manufacturers will phase in cleaner cars and light-duty trucks in the OTR according to a schedule that would accomplish emission reductions in the OTR basically equivalent to the following schedule:

  • 40% TLEVS for model years 1997-2000
  • 30% LEVs for model year 1999
  • 60% LEVs for model year 2000
  • 100% LEVs for model years 2001 and later


  • 1997: 40% TLEV, 60% TIER I
  • 1998: 40% TLEV, 60% TIER I
  • 1999: 40% TLEV, 30% LEV, 30% TIER I
  • 2000: 40% TLEV. 60% LEV
  • 2001: 100% LEV