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Emission Standards

United States: California: Light-Duty ZEV Emission Standard

ZEV Requirements

The California Zero-Emission Vehicle (ZEV) regulation is applicable to new 2018 and later passenger cars, light-duty trucks, and medium-duty vehicles and allows these vehicles to be certified as ZEVs if they produce zero exhaust emissions of any criteria pollutant, precursor pollutant, or greenhouse gas, under any possible operational modes or conditions. Emissions from air conditioning systems are excluded [5083].

The minimum ZEV credit percentage requirement for each manufacturer is listed in Table 1 as the “Total ZEV Percent Requirement”; the percentage of the PCs and LDTs, produced by the manufacturer and delivered for sale in California. Annual production volume is the average production volume for the previous 3 years.

Table 1
ZEV requirements as percent of annual California production volume
Model YearTotal ZEV Percent RequirementMinimum ZEV floorTZEVs

Large volume manufacturers can meet the credit requirements with a combination of ZEVs and transitional zero electric vehicles (TZEVs). Credits from ZEVs must be used to the “Minimum ZEV floor” requirements that range from 2.0% in 2018 to 16.0% in 2025. The balance can be TZEVs.

Intermediate volume manufacturers (average California production volume not exceeding 20,000 units/year) can meet their entire requirement with TZEV credits. Small volume manufacturers (average California production volume not exceeding 4,500 units/year) are not required to meet the ZEV requirements. However, this does not prevent these manufacturers from producing ZEVs and/or TZEVs to generate credits that can be banked, sold or traded.

  • TZEV—In order to be considered a TZEV (i.e., PHEV or hydrogen vehicles), the following requirements have to be met: (1) 150,000 mile (240,000 km) LEV III SULEV 20 or 30 exhaust emission limits, (2) California evaporative emissions standards, (3) California OBD requirements, (4) 15 years/150,000 mile (10 years for a zero-emission energy storage device used for traction power) extended warranty.

    The TZEV credit is proportional to the UDDS equivalent all-electric range (EAER): TZEV Credit = [(0.01) * EAER + 0.30]. A minimum AER of 10 miles (16 km) is required to qualify (0.4 credits). Credits increase to a maximum of 1.10 for AER of 80 miles (128 km). US06 all electric range capability (AER) ≥ 10 miles (16 km) provides an additional 0.2 credits. Hydrogen IC engine vehicles with minimum 250 UDDS miles (400 km) range also earn 0.75 credits with zero AER capability and up to 1.25 credits with electric-only driving capability.

  • ZEV—Credits are based on UDDS range: ZEV Credit = [(0.01) * (UDDS range) + 0.50]. A minimum 50 mile (80 km) range is required to qualify (1 credit) while credits are capped at 4 per ZEV when UDDS range ≥350 mile (560 km).

    Manufacturers that have complied with optional Section 177 state compliance path requirements for MY 2009-2017 vehicles can have their ZEV requirements lowered for MY 2018-2021. Hydrogen fuel cell vehicles placed in other Section 177 states can earn credits in California.

  • NEV—Neighborhood electric vehicles (NEVs) can earn a credit of 0.15 if they meet minimum performance requirements.
  • BEVx—Range extended battery electric vehicles (BEVx) must meet TZEV requirements, requirements on APU operation and have a minimum of 75 miles (120 km) UDDS all-electric range to qualify for ZEV credits. Credits are calculated as per ZEVs and are based on the all electric UDDS range.

Additional ZEV credits are available for medium duty ZEVS, Advanced Technology Demonstrations using ZEVs and ZEVs and TZEVs placed in Transportation Systems.

Use of ZEV Credits

A manufacturer may meet the ZEV requirements in a given model year by submitting the required amount of ZEV credits. Credits produced from TZEVs may be used to comply with the portion of the requirement that may be met with credits from TZEV, but not with the portion that must be satisfied with credits from ZEVs. These credits may be earned previously by the manufacturer or acquired from another party.

Discounted PZEV and AT PZEV credits and NEV credits may be used to satisfy up to 25% of the portion of a manufacturer’s requirement that can be met with credits from TZEVs. Intermediate volume manufacturers may fulfill their entire requirement with discounted PZEV and AT PZEV credits, and NEV credits in model years 2018 and 2019. These credits may be earned previously by the manufacturer or acquired from another party. Discounted PZEV and AT PZEV credits may no longer be used after model year 2025 compliance.

BEVx credits may be used to satisfy up to 50% of the portion of a manufacturer’s requirement that must be met with ZEV credits.

ZEV credits can also be earned by over compliance with GHG requirements. A manufacturer must submit its projected product plans to show over compliance with the CARB or EPA GHG requirements (by at least 2.0 gCO2/mile) in each model year from 2018 through 2021. It must also demonstrate its commitment to do so in each year. A manufacturer must apply for this option before 2017. Credits used to calculate GHG-ZEV over compliance credits must be removed from the manufacturer’s GHG compliance bank.

Credit = [(Manufacturer’s US PC and LDT Sales) × (gCO2/mile below manufacturer GHG standard for a given model year)] / (Manufacturer GHG standard for a given model year) (1)

A manufacturer may use no more than the percentage shown in Table 2 to meet either the total ZEV requirement nor the portion of their ZEV requirement that must be met with ZEV credits.

Table 2
Maximum GHG over-compliance credits that can be used towards ZEV requirements
Model Year2018201920202021
Max. Credit50%50%40%30%

For 2018 and subsequent model year, manufacturers may only meet up to 50% of the portion of their requirement that must be met with credits from ZEVs from a combination of credits earned under various flexibilities in the ZEV regulations.

Electric Vehicle Charging Requirements

Model year 2006 and later BEV, BEVx and PHEV vehicles must be equipped with a charging system which meets AC Level 1 and Level 2 charging as per SAE J1772 REV JAN 2010, SAE Electric Vehicle and Plug in Hybrid Electric Vehicle Conductive Charger Coupler. These vehicles must also be equipped with an on-board charger with a minimum output of 3.3 kW or sufficient power to enable a complete charge in less than 4 hours [5084].