Overview Of The National Low Emission Vehicle Program: Notes

Emission Reduction Stages:

While OBD II has the function of monitoring for emission related faults and alerting the operator of the vehicle, the National Low Emission Vehicle Program requires a certain number of vehicles produced (specific to manufacturing totals) currently comply with the following emission stages;

TLEV: Transitional Low Emission Vehicle

LEV: Low Emission Vehicle

ULEV: Ultra Low Emission Vehicle.

Prior to the National Low Emission Vehicle Program, the most stringent exhaust reduction compliancy is what is known internally within BMW as HC II. The benefit of exhaust emission reductions that the National Low Emission Vehicle Program provides compared with the HC II standard is as follows:

TLEV - 50% cleaner.

LEV - 70% cleaner.

ULEV -84% cleaner.

Fig 1: Exhaust Emission Permissible Value Chart

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: OBD II Evaporation Emission Compliance

Courtesy of BMW OF NORTH AMERICA, INC.