The EPA and NHTSA said the Phase 2 standards are expected to lower carbon dioxide (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 2 billion barrels over the lifetime of the vehicles sold under the program.
Both agencies claim that the “typical buyer” of a new long-haul truck in 2027 could recoup the extra cost of the technology in just less than two years through fuel savings. In total, the program is expected to result in up to $230 billion in “net benefits” to society over the lifetime of vehicles sold under the program: benefits that include fuel savings, carbon reductions, improved health, better energy security, along with lower travel and refueling costs.
Class 7 and 8 tractors and their engines account for roughly 60% of total GHG emissions and fuel consumption from the heavy-duty sector, according to EPA and NHTSA, and the Phase 2 standards for them start in model year 2021, increase incrementally in model year 2024, and are expected to be fully phased-in by model year 2027. The standards differ by vehicle weight class, roof height, and cab type (sleeper or day cab). The fully phased-in standards are expected to achieve up to 25% lower CO2 emissions and fuel consumption levels compared to the Phase 1 standards, EPA and NHSTA said.
OEMs can meet the tractor standards via several avenues: improvements to engines, transmissions, drivelines, and aerodynamic design, along with the use of lower rolling resistance tires, extended idle reduction technologies, and other accessories.
For diesel engines, Phase 2 standards begin to be applied in model year 2021, with interim standards to be met by 2024 before full phase-in occurs in model year 2027. A revised test cycle is being adopted as well for “weighting” tractor engines to better reflect actual in-use operation. 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, EPA and NHTSA said.
Technologies that could be used to meet the Phase 2 diesel engine standards include: combustion optimization; improved air handling; reduced friction within the engine; improved emissions after-treatment technologies; and waste heat recovery.
The Phase 2 program includes first-ever fuel efficiency standards for trailers. Compliance with the EPA’s Phase 2 GHG standards are voluntary starting in 2018, and are also voluntary for NHTSA from 2018 to 2020, with mandatory standards beginning in 2021. In general, the trailer standards apply only for box vans, flatbeds, tankers, and container chassis. Full compliance with the Phase 2 standards for trailers is expected by model year 2027; standards that should achieve up to 9% lower CO2 emissions and fuel consumption compared to an average model year 2017 trailer.
EPA and NHTSA said that some of the technologies trailer makers may use to meet the Phase 2 standards include: aerodynamic devices, lower rolling resistance tires, automatic tire inflation systems, and weight reducing designs.
Heavy- and medium- duty pickup trucks and vans represent about 23% of the fuel consumption and GHG emissions within the heavy- and medium-duty vehicle sector, EPA and NHTSA noted. The Phase 2 standards for heavy-duty pickups and vans, however, will apply largely in the same manner as the Phase 1 standards. Under this approach, all manufacturers face the same standards, but the average emission and fuel consumption rates applicable to each manufacturer depend on the manufacturer’s sales mix, with higher capacity vehicles (in terms of payload and towing) having less stringent targets.
Thus the Phase 2 standards for pickups and vans take the form of a set of target standard curves, based on a “work factor” that, as in Phase 1, combines a vehicle’s payload, towing capabilities, and whether or not it has 4-wheel drive. The standards become 2.5% more stringent every year from model years 2021 to 2027, with fully phased-in reductions in CO2 emissions and fuel consumption of about 16% beyond Phase 1.
EPA and NHTSA believe most pickup and van manufacturers will choose to meet the Phase 2 rules some of the same technologies already being used to meet the Phase 1 2014-2018 standards, including improvements in engines, transmissions, and lower rolling resistance tire technologies. Under Phase 2, though, both agencies expect newer, more advanced technologies such as engine stop/start and powertrain hybridization will introduced more broadly into this segment.
Vocational vehicles encompass a broad variety of units, including delivery trucks, emergency vehicles, cement and dump trucks, refuse haulers, public utility trucks, plus transit, shuttle, and school buses. Vocational vehicles represent about 17% of the total medium- and heavy-duty fuel consumption, EPA and NHTSA said, noting that Phase 2 rules for this segments start in model year 2021, with increased stringency in model year 2024 and full compliance by 2027.
Vocational vehicle standards will be differentiated using vehicle weights, driving cycle, and chassis type for emergency vehicles, cement mixers, coach buses, school buses, transit buses, refuse trucks, and motor homes may optionally use application-specific standards. The fully phased-in Phase 2 standards should achieve up to 24% in CO2 emissions and fuel consumption relative to Phase 1, the agencies predict, with improvements to engines, transmissions, and drivelines, plus the addition of lower rolling resistance tires, idle reduction systems, weight reducing designs, and some application of hybrid technology, to be used to gain compliance with the new rules.
The Phase 2 rules also include averaging, banking, and trading (ABT) compliance provisions for both the engine and vehicle standards in this program. EPA and NHTSA said such provisions allow manufacturers to trade credits, bank credits for future years, and average credits, which in turn allows manufacturers to certify engines or vehicles that do not perform up to the standard and offset them with engines or vehicles that perform better than the standard.
However, EPA and NHTSA said they are not adopting a full ABT program for the Phase 2 trailer standards because, in their words, “the nature of the industry makes it a challenge for trailer manufacturers to benefit from this type of program.” Instead, the agencies will finalize an averaging program available in model year 2027 for manufacturers of dry and refrigerated box vans as well as exemptions for non-box specialty trailer types that remove or reduce the burden for many small businesses.
The Phase 2 standards are fully aligned between EPA and NHTSA noted that the Phase 2 standards are “fully aligned” between them both as well as with the California Air Resources Board (CARB) so as to allow manufacturers to continue to build a “single fleet” of vehicles, equipment and engines for the U.S. market.