Vehicle Categories

Light-Duty Vehicles

California uses the same Light-Duty Vehicle definitions as the US EPA.

Heavy-Duty Vehicles

California uses its own unique definitions for regulating Heavy-Duty Vehicles that are 14,000-19,500 lbs GVWR.

Heavy-duty vehicles are defined as vehicles of GVWR (gross vehicle weight rating) of above 14,000 lbs in California (model year 1995 and later). Diesel engines used in heavy-duty vehicles are further divided into service classes by GVWR, as follows.

• Light heavy-duty diesel engines: 14,000 < LHDDE < 19,500, 1995+
• Medium heavy-duty diesel engines: 19,500 ≤ MHDDE ≤ 33,000
• Heavy heavy-duty diesel engines (including urban bus): HHDDE > 33,000

Additional designations by fuel type

In addition to standard EPA definitions, California regulations also include the following important definitions:

• Clean alternative fuel – any fuel used as the certification fuel in a low-emission vehicle, other than the primary gasoline or diesel fuel used in exhaust emission certification testing pursuant to CARB’s “California Exhaust Emission Standards and Test Procedures for 1988 Through 2000 Model Passenger Cars, Light-Duty Trucks and Medium-Duty Vehicles” as incorporated by reference in Title 13, California Code of Regulations, section 1960.1, or “California Exhaust Emission Standards and Test Procedures for 2001 and Subsequent Model Passenger Cars, Light-Duty Trucks, and Medium-Duty Vehicles.”
• Designated clean fuel – means any clean alternative fuel other than electricity
• Low emission vehicle – any vehicle certified to the LEV (Low Emission Vehicle), TLEV (Transitional Low-Emission Vehicle), SULEV (Super Ultra Low Emission Vehicle), or ZEV (Zero Emission Vehicle) standard.