The US Environmental Protection Agency (EPA) its Tier 3 emission standards for gasoline sulfur content; evaporative emissions; and tailpipe emissions from passenger cars, light-duty trucks, medium-duty passenger vehicles, and some heavy-duty vehicles. EPA had issued the proposed standards last March. (Earlier post.)
The Tier 3 standards, which come into effect starting in 2017, consider the vehicle and its fuel as an integrated system. The gasoline sulfur standard will make emission control systems more effective for both existing and new vehicles, and will enable more stringent vehicle emissions standards since removing sulfur allows the vehicle’s catalyst to work more efficiently. The Tier 3 standards are also closely coordinated with California’s LEV III standards as well as with EPA’s and California’s programs for greenhouse gas (GHG) emissions from light-duty vehicles.
The tailpipe standards include different phase-in schedules that vary by vehicle class but generally phase in between model years 2017 and 2025. In addition to the gradual phase-in schedules, other flexibilities include credits for early compliance and the ability to offset some higher-emitting vehicles with extra-clean models.
Gasoline sulfur. Under the final Tier 3 program, federal gasoline will not contain more than 10 parts per million (ppm) of sulfur on an annual average basis by 1 January 2017. EPA is also finalizing standards that maintain the current 80 ppm refinery gate and 95 ppm downstream cap. The Tier 3 gasoline sulfur standards are similar to levels already being achieved in California, Europe, Japan, South Korea, and several other countries.
The fuel sulfur standards include an averaging, banking, and trading (ABT) program that will 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 finalizing flexibilities such as the ability to carry over credits from Tier 2 to Tier 3 and hardship provisions for extenuating circumstances, as well as flexibility provisions for small businesses (small manufacturers of Tier 3 vehicles and small refiners), small volume manufacturers, and small volume refineries.
EPA said it received a large number and wide range of comments on the proposed rule, and the final Tier 3 program is based both on this extensive public input and updated analyses of the rule’s impacts. EPA sought comment on the level of the per-gallon sulfur cap (which applies in addition to the annual average), and decided to maintain the per-gallon caps at existing levels. EPA is also finalizing an ethanol content of 10% (E10) for emissions test gasoline (as opposed to the proposed 15% ethanol (E15) test fuel).
Tailpipe emissions. EPA is setting new tailpipe standards for the sum of non-methane organic gases (NMOG) and nitrogen oxides (NOx), presented as NMOG+NOx, and for particular matter (PM) that apply to all light-duty vehicles and some heavy-duty vehicles.
Compared to current standards, the NMOG and NOx tailpipe standards for light-duty vehicles represent approximately an 80% reduction from today’s fleet average and a 70% reduction in per-vehicle PM standards. Heavy-duty tailpipe standards represent about a 60% reduction in both fleet average NMOG+NOX and per-vehicle PM standards. EPA is also extending the regulatory useful life period during which the standards apply from 120,000 miles to 150,000 miles.
The tailpipe standards include different phase-in schedules that vary by vehicle class, but generally phase in between model years 2017 and 2025. In addition to the gradual phase-in schedules, several other provisions are designed to further ease manufacturers’ paths to compliance with the stringent new standards. Depending on the standards and the vehicle class, these flexibility provisions include credits for early compliance and the ability to offset some higher-emitting vehicles with extra-clean models. EPA is also finalizing more lead time for small businesses and small volume manufactures as well as a hardship provision that allows for additional time to comply if a manufacturer cannot meet requirements after a good faith effort and would face severe economic hardship without the additional lead time.
The standards for NMOG+NOx are fleet-average standards—i.e., 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+NOx 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 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 standards decline from today’s fleet average of about 200 mg/mi to 50 mg/mi by 2025.
NMOG+NOx 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 fleet average standards decline from today’s fleet average of 395 mg/mi to 178 mg/mi for Class 2b vehicles and 630 mg/mi to 247 mg/mi for Class 3 vehicles by 2022. Additional standards for emissions measured over a heavy-duty SFTP are being set for the first time and vary by vehicle class and power-to-weight ratio.
The PM standards are expressed on a per-vehicle basis, meaning the standards apply to each vehicle separately—i.e., not as a fleet average. EPA is setting PM standards that 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 per-vehicle 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 standard for all light-duty vehicles is 10 mg/mi through MY 2018 and 6 mg/mi for 2019 and later model years. These standards are lower than what was proposed based on more recent data supporting a numerically lower US06 PM standard.
PM Standards for Heavy-Duty Pick-ups and Vans; Class 2b and 3. As measured on the FTP, the per-vehicle PM standards are 8 mg/mi for Class 2b vehicles and 10 mg/mi for Class 3 vehicles. EPA is also setting PM standards for emissions measured over the SFTP with standards levels and duty cycles varying by vehicle class and power-to-weight ratio.
Evaporative Emission Standards. EPA is setting more stringent standards designed to eliminate fuel vapor-related evaporative emissions and improve durability. The evaporative emissions program represents about a 50% reduction from current standards and applies to all light-duty and on-road 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 and a hardship provision for small businesses and small volume manufacturers. EPA is also extending 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. The final 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 on-road gasoline-powered heavy-duty vehicles.
Bleed Test Requirements. EPA is setting 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 on-road gasoline- powered heavy-duty vehicles is 0.030 g/test without averaging.
Leak Test and Emission Standard. EPA is finalizing a new emission standard and test procedure requiring 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 adopting and incorporating by reference the California Air Resources Board’s (CARB) current OBD regulations, effective for MY 2017, with only minor differences. These requirements cover all vehicles except those in the heavier fraction of the heavy-duty vehicle class.
Emissions Test Fuel. EPA is updating 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 apply to new vehicle certification, assembly line, and in-use testing.
EPA is transitioning 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 10% ethanol by volume, lowering octane, and lowering the existing sulfur specification to be consistent with Tier 3 requirements. EPA is also setting test fuel specifications for E85 for the first time.
Costs and benefits. EPA estimates that by 2030 up to 2,000 premature deaths, 50,000 cases of respiratory ailments in children, 2,200 hospital admissions and asthma-related emergency room visits, and 1.4 million lost school days, work days and days when activities would be restricted due to air pollution. Total health-related benefits in 2030 will be between $6.7 and $19 billion annually. The program will also reduce exposure to pollution near roads. More than 50 million people live, work, or go to school in close proximity to high-traffic roadways, and the average American spends more than one hour traveling along roads each day.
EPA says the final standards will provide up to 13 dollars in health benefits for every dollar spent to meet the standards, more than was estimated for the proposal. The sulfur standards will cost less than a penny per gallon of gasoline on average once the standards are fully in place. The vehicle standards will have an average cost of about $72 per vehicle in 2025.