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:
|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)|
|*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|
|Category||Existing NMOG standards a|
emission standards b|
|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