California to keep pushing for more stringent regulations
The California Air Resources Board (CARB) announced its support for the new Phase 2 MDHD rulemaking. However, the state agency noted, to meet California’s long-term greenhouse gas goals out to 2050, more stringency will be needed, even after the Phase 2 standards are fully implemented in 2027.
CARB said it looked forward to continued cooperation with the federal agencies on this long-term effort.
In addition, CARB is looking forward to working with the federal agencies to develop new, lower NOx standards. In order to achieve the 2008 Ozone National Ambient Air Quality Standards set by US EPA, CARB estimates that the South Coast Air Basin alone (including Los Angeles) will need an 80% reduction in NOx emissions by 2031.

The agencies are also finalizing fuel-efficiency and GHG standards for trailers for the first time. The EPA trailer standards, which exclude certain categories such as mobile homes, will begin to take effect in model year 2018 for certain trailers, while NHTSA’s standards will take effect as of 2021, with credits available for voluntary participation before then.

Cost-effective technologies for trailers—including aerodynamic devices, light weight construction and self-inflating tires—can significantly reduce total fuel consumption by tractor-trailers, while paying back the owners in less than two years due to the fuel saved. Recognizing that many trailer manufacturers are small businesses, the program includes provisions that reduce burden, such as a one-year delay in initial standards for small businesses and simplified certification requirements.

Compared to the original proposal, the final program:

• Achieves 10% more GHG and fuel consumption reductions;

• Has more robust compliance provisions, including improved test procedures, enhanced enforcement audits and protection against defeat devices;

• Includes more stringent diesel engine standards;

• Improves the vocational vehicle program with a regulatory structure better tailored to match the right technology for the job; and

• Maintains the structure and incremental phase-in of the proposed standards, allowing manufacturers to choose their own technology mix and giving them the lead time needed to ensure those technologies are reliable and durable.

The Phase 2 standards maintain the underlying regulatory structure developed in the Phase 1 program, such as the general categorization of medium- and heavy-duty vehicles and the separate engine standards. Under Phase 2, agencies are additionally adopting first-time CO₂ and fuel efficiency standards for certain trailers used with heavy-duty combination tractors. Specifically, EPA’s CO₂ emissions standards and NHTSA’s fuel consumption standards are tailored to each of four regulatory categories of heavy-duty vehicles:

1. Combination Tractors;

2. Trailers Pulled by Combination Tractors;

3. Heavy-duty Pickup Trucks and Vans; and

4. Vocational Vehicles, which include all other heavy-duty vehicles such as buses, refuse trucks, and concrete mixers.

The program also includes separate standards for the engines that power combination tractors and vocational vehicles.

As with the Phase 1 program, the agencies are adopting separate standards and test cycles for tractor engines, vocational diesel engines, and vocational gasoline engines.

For diesel engines, the standards begin in model year 2021 and phase in to model year 2027, with interim standards in model year 2024. The final diesel engine standards will reduce CO₂ emissions and fuel consumption by up to 5% for tractor engines and up to 4% for vocational engines compared to Phase 1.

Technologies that could be used to meet the standards include: combustion optimization; improved air handling; reduced friction within the engine; improved emissions after-treatment technologies; and waste heat recovery.

The final standards are expected to lower CO₂ emissions by approximately 1.1 billion metric tons, save vehicle owners fuel costs of about $170 billion, and reduce oil consumption by up to two billion barrels over the lifetime of the vehicles sold under the program.

Overall, according to the government models, the program will provide $230 billion in net benefits to society, outweighing costs by about an 8-to-1 ratio.

The final rulemaking builds on the fuel efficiency and GHG emissions standards already in place for model years 2014-2018, which alone will result in CO₂ emissions reductions of 270 million metric tons and save vehicle owners more than $50 billion in fuel costs. Truck sales were up in model years 2014 and 2015, the years covered under the first round of truck standards.

Heavy-duty trucks are the second largest segment and collectively make up the biggest increase in the US transportation sector in terms of emissions and energy use. These vehicles currently account for about 20% of GHG emissions and oil use in the US transportation sector. Globally, GHG emissions from heavy-duty vehicles are growing rapidly and are expected to surpass emissions from passenger vehicles by 2030.

NHTSA and EPA have worked together to harmonize their standards under this program. The agencies have worked closely with the State of California’s Air Resources Board in developing and finalizing the standards. All three agencies are committed to the goal of setting harmonized national standards.

Resources

• Final rule: Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles - Phase 2