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California ARB LEV III Concept Targeting Fleet-Average SULEV-Level Emissions Performance from New Vehicles by MY 2022

Illustration of light-duty vehicle sales share by emission certification level projected to be required to meet proposed NMOG+NOx standards in new LEV III. Source: ARB. Click to enlarge.

The California Air Resources Board (ARB) is developing a proposal for more stringent emission requirements—i.e., LEV III—for new passenger vehicles, to be considered by the Board later this year. (Earlier post.)

According to a newly-published discussion paper, the primary objective of the proposed standards is to require fleet average SULEV-level emissions performance (similar to the Federal Tier 2 Bin 2 standard) from new vehicles by model year 2022. Among the areas of proposed modifications are increased stringency and restructuring of the NMOG and NOx standards; increased stringency for PM standards; increased durability requirements for emission control systems; expanded coverage of more restrictive evaporative control requirements; and new requirements for supplemental test procedure emission testing.

ARB will hold a one-day workshop on 2 March to discuss its preliminary thoughts and sources of information upon which to base the proposed standards and procedures.

Regarding future Greenhouse Gas (GHG) emission regulations (Pavley 2), staff is evaluating studies of the feasibility and cost of advanced technologies to reduce GHG emissions that could achieve widespread sales and acceptance in the 2017-2025 timeframe. At the workshop, staff will also discuss these studies and welcomes input from stakeholders.


The existing LEV II program regulates emissions from new light-duty vehicles, including include all passenger cars, light trucks, and medium-duty passenger vehicles.
The current set of standards, in the order of increasing stringency, includes the emission category designations:
  • Low-Emission Vehicle (LEV);
  • Ultra Low-Emission Vehicle (ULEV); and
  • Super Ultra Low-Emission Vehicle (SULEV).
  • Each certification level has its own permissible emission levels for non-methane organic gases (NMOG), oxides of nitrogen (NOx), formaldehyde (HCHO), carbon monoxide (CO), and particulate matter (PM). Different emission standards are established for intermediate full useful life (50,000-miles) and full useful life (120,000-miles) durability.
    Based on model year 2008 NMOG certification data for vehicles sold in California, 22% of new vehicles are certified as LEV, 55% as ULEV, and 22% as SULEV.

    Despite the progress that has been made to date, major reductions of criteria pollutant emissions in California are still required to achieve mandated State and federal ambient air quality standards, according to ARB. The majority of California residents live in areas that do not meet permissible air quality levels for regulated air pollutants—mostly due to exceedances in atmospheric concentrations of ozone and particulate matter.

    Light-duty passenger cars and trucks are responsible for a major fraction of ozone- forming emissions: NOx (15% of California emissions), CO (42%), and ROG (21%). In addition, light-duty vehicles are responsible for lesser portions of California’s overall particulate matter (PM) emissions (2% of PM10 and 3% of PM2.5).

    LEVII criteria pollutant emission standards (PC/LDT1 and LDT2)
    CategoryDurability basis
    LEV 50,000 0.075 0.05 3.4 0.015
    120,000 0.090 0.07 4.2 0.018 0.01
    ULEV 50,000 0.040 0.05 1.7 0.008
    120,000 0.055 0.07 2.1 0.011 0.01
    SULEV 120,000 0.010 0.02 1.0 0.004 0.01
    PZEV* 150,000 0.010 0.02 1.0 0.004 0.01
    *PZEV has same test emission levels as SULEV but includes additional evaporative emissions control and a 150,000-mile warranty.

    ARB staff is developing several major proposed modifications to the LEV program for the new LEV III regulations, with the fleet SULEV goal in mind.

    New NMOG + NOx standard. The LEV III proposal combines NMOG and NOx standards into one NMOG+NOx standard; introduces a more stringent combined NMOG+NOx fleet average requirement for 2014-2022 model years; adds several emission standard bins; and increases the durability requirements for emission control systems.

    ARB staff says that the primary logic for combining the two pollutants is to provide greater flexibility for manufacturers to reduce emissions with new emission control technologies. Staff’s technical research and industry input indicate that there are a number of technologies that are more effective in reducing one pollutant than the other, and vice versa.

    ARB staff is proposing that the fleet-wide target for LEV III emissions for model year 2022 be equivalent to the combined NMOG+NOx value of the existing SULEV emission standard. The existing SULEV emission levels are 0.020 g NMOG/mile and 0.01 g NOx/mile, for a combined emission level of 0.030 g NMOG+NOx/mile. Therefore, the proposed change from today’s fleet average emissions to the fully phased-in fleet-wide SULEV emission level would result in a decrease in NMOG+NOx emissions from 0.112 to 0.030 g/mi—a 73% reduction.

    —LEV III discussion paper

    To provide a path for a gradual evolution toward new emission control technology, the existing regulatory system would be expanded from three emission categories (LEV, ULEV, and SULEV) to six emission categories (adding ULEV70, ULEV50, and SULEV20) that could be utilized by manufacturers for fleet emission averaging.

    Proposed LEV III NMOG+NOx Emission Standards
    CategoryExisting NMOG standards a
    Existing NOx standards a
    Combined NMOG+NOx standards
    Proposed NMOG+NOx emission standards b
    LEV 0.090 0.070 0.160 0.160
    ULEV 0.055 0.070 0.125 0.125
    ULEV70 0.070
    ULEV50 0.050
    SULEV 0.020 0.010 0.030 0.030
    SULEV20 0.020
    a 120,000-mile durability basis
    b 150,000-mile durability basis.

    Medium-duty vehicles. Medium-duty vehicles (MDVs) are either certified using the chassis dynamometer test procedure or by the engine dynamometer test procedure. Vehicles that are engine certified include incomplete gasoline vehicles and those powered with diesel engines. Currently, manufacturers are required to certify 40% of their chassis-certified vehicles to the LEV standard and 60% to the ULEV standard. All vehicles certified using the engine dynamometer test procedure must certify to the ULEV standard.

    Under the LEV III proposal, ARB is not proposing to modify the emission standards for engine dynamometer certified vehicles. However, ARB staff is proposing to combine the NMOG+NOx standards and increase the stringency of the emission requirements for chassis-certified MDVs.

    PM Standard. The existing particulate matter (PM) standard for LEV, ULEV, and SULEV certification levels is 0.01 g PM/mile, or 10 milligrams/mile (mg/mi). Since gasoline vehicles emit generally at or below 1.0 mg PM/mi, or about 90% lower than the standard, the primary impact of the 10 mg/mi standard has been to assure the use of particulate filters on diesel-fueled vehicles.

    ARB staff is proposing to reduce the permissible PM levels for new vehicles.

    The stringency of the proposed PM standard has not been determined; however, staff is interested in ensuring foremost that new vehicle PM emissions levels do not gradually increase due to the emergence of new increased combustion efficiency engines. To ensure that PM emissions do not increase, the new PM standard will likely be between 2 and 4 mg/mile, depending on ongoing ARB emission testing and analysis.

    One important determination will be whether the proposed PM standard would effectively require particulate filters for gasoline direct injection technology, which is expected to become widespread as manufacturers comply with federal GHG regulations from model years 2012-2016. Staff has received input from a number of manufacturers suggesting that a standard of 3 mg PM/mi can be met for gasoline direct injection engines without requiring the use of particulate filters.

    —LEV III discussion paper

    Durability. To help reduce this gap between the durability requirement and real-world vehicle lifetime, the LEV III proposal would phase-in a new 150,000-mile durability requirement.

    Evaporative emissions. Staff proposes to require all light-duty vehicles to comply with the zero evaporative standard. This would result in at least a 30% emission reduction from current evaporative emissions.

    In addition...staff proposes to update the California certification gasoline specifications to include approximately 10% ethanol by volume (E10), which is representative of what is now sold at the pump. Staff believes the technology required to meet the zero evaporative standard even on arguably a more “severe” fuel such as E10 (i.e., in terms of potentially generating more evaporative emissions) is available and cost-effective.

    —LEV III discussion paper



    Stan Peterson

    When you are a bureaucrat and your job is in jeopardy because what you regulate has been cured.

    Why simply move the goalpost.

    There is no evidence that existing SULEV standards together with evaporative emissions regulations that constitute PZEV, will not create great air quality across the USA. It has brought all but two cities into "Air Quality attainment", bureaucrat duck speak for job accomplished.

    Only Houston and Los Angeles does qualify at present. Recent new regulations over the past few years will bring large diesels in trucks, locomotives, marine. construction and farm equipment into regulation. Similarly applying regulations for small lawn mower gas engines has been done.

    That should be plenty to meet Air "Quality Attainment" standards in the two laggard cities, as well as providing additional margins for exceeding air quality across the US that needs little but time for further improvement.

    Codifying SULEV as a requirement for all vehicles is fine; the diesel tightening is good in that it extends diesel cleanliness to the equivalent of modern gasoline engine accomplishments.

    All the rest is useless window dressing, meant to justify CARB's further existence, and nothing more. Now the Forty year War on Air Pollution is almost won.

    Shouldn't we be talking about demobilizing the wartime army into a smaller peacetime standing force? Shouldn't we be planning other uses for the "peace dividend"?

    Stan Peterson


    Only Houston and Los Angeles does Not qualify at present...

    Stan Peterson

    The diagram accompanying the proposal reveals that almost 25% of the auto fleet already achieves SULEV or PZEV levels of cleanliness. If the CARB did nothing except simply wait to let the older vehicles eventually be scrapped; and be replaced with new, cleaner vehicles. Then virtually all the gasoline powered vehicles will meet SULEV, and be clean air cars equal to FCEVs or BEVs.

    It proves the only thing really needed is to tighten diesel emission regulations to the equivalent of new gasoline vehicles now entering the fleet.

    The 20% LEV portion of the fleet today consists almost entirely of really old cars and diesels.

    All this has been accomplished despite NO REQUIREMENT that auto makers meet SULEV today.

    Proving once again, that big bad capitalists do not want their families to breathe bad air either, they are not the evil doers of Socialist theologians and propagandists.


    This is almost unbelievable. Is it April 1st?

    I lived in CA for many years
    and still have many family members there
    and it is NOT true that Californians are all just chunks of granola
    but most of the politicians really are nuts, fruits or flakes.


    Diversity of opinion is sometime unpleasant and may irritate many but can be informative.

    Continously calling others fools and ignorants is questionable.



    In general I agree with you. Except for CARB. They represent the (local) politicizing of technology of the worst kind. Remember these are the clowns that espoused the hydrogen economy (at the expense of BEVs) 8-10 years ago.

    They used their political power to advance very poor technical decisions. They've hurt the country in its effort to wean itself from fossil fuels. Stupid people in power can be very dangerous.


    Well, maybe not stupid, Jim. But not well informed. Gauging the benefits of EV over FCs is not a difficult call for those immune to political influence. CARB is infiltrated with politics.

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