Vehicle emissions

The proposed vehicle emission standards, combined with the proposed reduction of gasoline sulfur content, would significantly reduce motor vehicle emissions, including nitrogen oxides (NO_x), volatile organic compounds (VOC), direct particulate matter (PM_2.5), carbon monoxide (CO) and air toxics.

Compared to current standards, the proposed non-methane organic gases (NMOG) and nitrogen oxides (NO_x), presented as NMOG+NO_x, tailpipe standards for light-duty vehicles represent approximately an 80% reduction from today’s fleet average and a 70% reduction in per-vehicle particulate matter (PM) standards.

The proposed standards for NMOG+NO_x are fleet-average standards, meaning that a manufacturer calculates the weighted average emissions of the vehicles it produces in each model year and compares that average to the applicable standard for that model year. The standards differ by vehicle class and test cycle. Key elements include:

NMOG+NO_x Standards for Light-Duty Vehicles and Light-Duty Trucks (vehicles below 8,500 pounds (lbs) Gross Vehicle Weight Rating (GVWR)), and Medium-Duty Passenger Vehicles (8,500 to 10,000 lbs GVWR):

• As measured on the Federal Test Procedure (FTP), the proposed standards decline from today’s fleet average of 160 milligrams per mile (mg/mi) to 30 mg/mi by 2025.

• As measured on the Supplemental Federal Test Procedure (SFTP), the proposed standards decline from today’s fleet average of about 100 mg/mi to 50 mg/mi by 2025.

NMOG+NO_x Standards for Heavy-Duty Pick-ups and Vans; Class 2b (8,501-10,000 lbs GVWR) and Class 3 (10,001-14,000GVWR):

• As measured on the FTP, the proposed fleet average standards decline from a fleet average of 278 mg/mi to 178 mg/mi for Class 2b vehicles and 451 mg/mi to 247 mg/mi for Class 3 vehicles by 2022.

• Additional standards for emissions measured over a heavy-duty SFTP are being proposed for the first time and vary by vehicle class and power-to-weight ratio.

PM Standards

The proposed PM standards are expressed on a per-vehicle basis, meaning the standards would apply to each vehicle separately (i.e., not as a fleet average). EPA is proposing PM standards that would differ by vehicle class and test cycle. Key elements include:

PM Standards for Light-Duty Vehicles, Light-Duty Trucks, and Medium-Duty Passenger Vehicles:

• As measured on the FTP, the proposed standard is 3 mg/mi for all vehicles and for all model years, as compared to today’s standard of 10 mg/mi.

• As measured on the US06, a high-speed, fast-acceleration component of the SFTP, the proposed standard is 10 mg/mi for lighter vehicles and 20 mg/mi for heavier vehicles.

PM Standards for Heavy-Duty Pick-ups and Vans; Class 2b and 3:

• As measured on the FTP, the proposed PM standards are 8 mg/mi for Class 2b vehicles and 10 mg/mi for Class 3 vehicles.

• PA is also proposing PM standards for emissions measured over the SFTP with standards levels and duty cycles varying by vehicle class and power-to-weight ratio.

The proposed heavy-duty tailpipe standards represent about a 60% reduction in both fleet average NMOG+NO_x and per-vehicle PM standards. EPA is also proposing to extend the regulatory useful life period during which the standards apply from 120,000 miles to 150,000 miles.

Evaporative emission standards

EPA is proposing more stringent standards designed to eliminate fuel vapor-related evaporative emissions and improve durability. The proposed evaporative emissions program represents about a 50% reduction from current standards and applies to all light-duty and onroad gasoline-powered heavy-duty vehicles.

As with the tailpipe standards, the evaporative emissions standards include phase-in flexibilities, credit and allowance programs, and more lead time for small businesses and small volume manufactures as well as a hardship provision. EPA is also proposing to extend the regulatory useful life period during which the standards apply from 120,000 miles to 150,000 miles. Key elements of the program include:

• Evaporative Emissions Standards: Proposed standards over 2-day and 3-day evaporative emission tests vary by vehicle categories and range from 0.300 g/test to 0.500 for light-duty vehicles and medium duty passenger vehicles, with 0.600 g/test for onroad gasoline-powered heavy-duty vehicles.

• Bleed Test Requirements: EPA is proposing a new testing requirement referred to as the bleed emission test. The bleed emissions test standard for light-duty and medium-duty passenger vehicles is 0.020 g/test without averaging. The standard for onroad gasoline- powered heavy-duty vehicles is 0.030 g/test without averaging.

• Leak Test and Emission Standard: EPA is proposing to add a new emission standard and test procedure that would require that the cumulative equivalent diameter of any orifices or “leaks” not exceed 0.02 inches anywhere in the fuel/evaporative system for light-duty vehicles, medium-duty passenger vehicles, and some gasoline-powered heavy-duty vehicles.

• Onboard Diagnostic System (OBD) Requirements: EPA is proposing to adopt and incorporate by reference the California Air Resources Board’s (CARB) current OBD regulations, effective for MY 2017, that would cover all vehicles except those in the heavier fraction of the heavy-duty vehicle class.

Gasoline

EPA is proposing that federal gasoline contain no more than 10 parts per million (ppm) of sulfur on an annual average basis by 1 January 2017, down from the current 30 ppm. In addition, EPA is proposing to either maintain the current 80-ppm refinery gate and 95-ppm downstream caps or lower them to 50 and 65 ppm, respectively. The proposed Tier 3 gasoline sulfur standards are similar to levels already being achieved in California, Europe, Japan, South Korea, and several other countries.

The Tier 2 Gasoline Sulfur program—which marked the first time EPA treated vehicles and fuels as a system—reduced the sulfur content of gasoline by up to 90% from uncontrolled levels. The final Tier 2 rule was published in 2000. Phased in from 2004-2007, and now in effect, the program allows refiners to produce gasoline with a range of sulfur levels as long as their annual corporate average does not exceed 30 parts per million (ppm). In addition, no individual batch can exceed 80 ppm.

The proposed fuel sulfur standards include an averaging, banking, and trading (ABT) program that would allow refiners and importers to spread out their investments through an early credit program and rely on ongoing nationwide averaging to meet the sulfur standard. EPA is also proposing flexibilities such as hardship provisions for extenuating circumstances, as well as flexibility pro­ visions for small businesses (small manufacturers of Tier 3 vehicles and small refiners), small volume manufacturers, and small volume refineries.

Proposed changes to emissions test fuel

EPA is also proposing to update the federal emissions test fuel to better match today’s in-use gasoline and also to be forward-looking with respect to future ethanol and sulfur content.

The new test fuel specifications would apply to new vehicle certification, assembly line, and in-use testing. EPA is proposing to transition to the new test fuel during the first few years that the Tier 3 tailpipe and evaporative standards are phasing in. Key changes include moving to a test fuel containing 15% ethanol by volume (seeking comment on 10% ethanol by volume), lowering octane, and lowering the existing sulfur specification to be consistent with proposed Tier 3 requirements. EPA is also proposing test fuel specifications for E85 for the first time.

Costs and impacts

EPA calculates that the program will cost about a penny per gallon of gasoline, and about $130 per vehicle. The annual cost of the overall program in 2030 would be approximately $3.4 billion; however, EPA estimates that in 2030, the annual monetized health benefits of the proposed Tier 3 standards would be between $8 and $23 billion.

EPA estimates that by 2030, the Tier 3 standards would annually prevent between 820 and 2,400 premature deaths; 3,200 hospital admissions and asthma-related emergency room visits; 22,000 asthma exacerbations; 23,000 upper and lower respiratory symptoms in children; and 1.8 million lost school days, work days and minor-restricted activities.

Once published in the Federal Register, the proposal will be available for public comment and EPA will hold public hearings to receive further public input.

Resources

• Proposed rule