Q: What Are California's Emissions Standards?

asked by on November 25, 2015

What are California's emissions standards?

The emissions standards for California are quite extensive. The state standards are more stringent than the federal standards and they cover a wide range of vehicle emission types. A growing number of other states, and foreign countries, are adopting California’s emissions standards for their areas.

In general, California emissions standards are divided into three levels: LEV (Low Emission Vehicle)/Tier 1, LEV II/Tier 2, and LEV III/Tier 3.

LEV standards are applied to vehicles through model year 2003. LEV II standards apply to model years 2004 - 2010. LEV III standards apply to model years 2015 - 2025.

Tier 1 vehicles are divided into three separate groups:

  • Passenger cars
  • Light duty trucks below 6000 GVWR
  • Light duty trucks above 6000 GVWR

Tier 2 encompasses all Tier 1 vehicles and includes light duty trucks above 8500 GVWR

Tier 3 replaces Tier 2

Within the LEV set of standards, there are further classifications of emissions by vehicle type. These include:

  • Transitional Low Emission Vehicles (TLEV)
  • Low Emission Vehicles (LEV)
  • Ultra Low Emission Vehicles (ULEV)
  • Super Ultra Low Emission Vehicles (SULEV)
  • Zero Emission Vehicles (ZEV)

California emissions standards cover much more, like heavy duty engines, off-road diesels, marine engines, and locomotives. What I’ve covered here is just a thumbnail sketch of the current legislation.

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