The federal government’s top vehicle and clean-air regulators on June 19 formally announced their proposal for extending fuel-economy and greenhouse-gas emissions rules, and predicted positive economic and health-benefit results.

Phase 2 of the regulations for 2021 to 2027-model trucks and tractors and 2018-to-2027 MY trailers would cover entire vehicles, and there will be separate rules for engines, said the Administrators of the National Highway Traffic Safety Administration and the Environmental Protection Agency, in a hurried press briefing today.

“The EPA trailer standards, which exclude certain categories such as mobile homes, would begin to take effect in model year 2018 for certain trailers, while NHTSA’s standards would be in effect as of 2021, with credits available for voluntary participation before then,” the agencies said in a joint press release issued prior to the briefing.

“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,” the release said.

About $10,000 to $12,000 in new equipment would be needed by a tractor-trailer to meet the requirements, said Gina McCarthy, EPA’s administrator.

Much off-the-shelf existing technology now used to meet current Phase 1 economy and GHG requirements can extend into Phase 2, but “innovative technology” will also be required, she said.

“Some of the new technology is now in development,” said Mark Rosekind, who heads the National Highway Traffic Safety Administration. “We heard from plenty of companies who say they will be available soon.” McCarthy added that, “Everybody will have lots of choice. “There will be no one path.”

The Phase 2 proposals resulted from “rigorous technical study” and more than 300 meetings with manufacturers, fleets, owner-operators, drivers, union leaders and others in the trucking industry, she said.

That’s why they know that the innovative technologies involving better engine combustion efficiency, among other things, are close to being ready, Rosekind commented.

The two officials declined to give mile-per-gallon estimates asked for several times by general media reporters during the call-in briefing. “There is no number to give,” Rosekind said, because medium- and heavy-duty trucks and combination vehicles vary greatly in configuration, weight and use.

“What matters is freight efficiency,” McCarthy said.

“Today’s proposal builds on the fuel efficiency and GHG emissions standards already in place for model years 2014-2018, which alone will result in emissions reductions of 270 million metric tons and save vehicle owners more than $50 billion in fuel costs,” the press release stated. “The current standards have been successful, with truck sales up in model years 2014 and 2015 due in part to improved fuel efficiency. 

“The proposal also builds on standards that the Administration has put in place for light-duty vehicles, which are projected to reduce carbon pollution by 6 billion tons over the lifetime of vehicles sold, double fuel economy by 2025, and save consumers $1.7 trillion at the pump. These standards are already delivering savings for American drivers; new vehicles in 2013 achieved their highest fuel economy of all time.”

A 60-day public comment period will follow the proposal’s publication in the Federal Register, the Administrators said. And NHTSA and EPA will host two public hearings and continue an “open-door policy of meeting with stakeholders over the course of the comment period.”