It’s official: The Environmental Protection Agency (EPA) and National Highway Traffic Safety Administration (NHTSA) on Tuesday published in the Federal Register 2,762 pages of the next truck fuel efficiency rule, “Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles - Phase 2.”

The rule was finalized in mid-August; Tuesday’s publication starts a 60-day countdown to the date the rule takes effect.

Called for by President Obama’s Climate Action Plan, the rule sets GHG emissions targets through 2027, and is a follow-up the Phase 1 targets put in place by the Obama administration in 2011. That initial round covered model years 2014-2018.

The rule regulates four "official" categories of commercial vehicles and related equipment: combination tractors; for the first time, trailers used in combination with those tractors; heavy-duty pickup trucks and vans; and vocational vehicles. 

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.

NHTSA projects the trucking industry should save somewhere between $7.8 billion to $8.5 billion per year due to the Phase 2 GHG rules.

“This rule builds on our commitment to robust collaboration with stakeholders and the public,” the agencies say in the executive summary of the rule. “It follows an expansive and thorough outreach effort in which the agencies gathered input, data and views from many interested stakeholders, involving over 400 meetings with heavy-duty vehicle and engine manufacturers, technology suppliers, trucking fleets, truck drivers, dealerships, environmental organizations, and state agencies.”

And then there are the more than 230,000 formally filed public comments, with the government response taking another 2,169 pages in the rulemaking docket.

Following up on the “win-win” Phase 1 truck fuel efficiency/greenhouse gas emissions standards, the Phase 2 goals are specific and challenging but the rule is flexible enough that truck and engine makers will be able to meet them without disruption, explained Sean Waters, director of compliance and regulatory affairs for Daimler Trucks North America. Waters spoke earlier this month at the American Trucking Assns. annual meeting.

“We picked low-hanging fruit first, the quick, easy wins for our customers,” Waters said, referring to the 2011 standards. “This is a much tougher rule. We’ll have to spend hundreds of millions of dollars in R&D to hit the targets, but we’re confident we can hit those targets in a way that will still provide benefits for our customers. If the technology saves the customer money at the end of the day, then they’re going to buy it and we’ll see environmental benefits as well as fuel economy benefits.”