EPA Proposal to Ease Diesel Emissions Compliance Could Improve Reliability for Motorcoach Operators

Motorcoach operators could see significant improvements in vehicle reliability and lower operating costs under a proposed rule announced by the US Environmental Protection Agency (EPA) that would overhaul portions of federal heavy-duty diesel emissions requirements.

The proposal, unveiled by EPA Administrator Lee Zeldin, would revise elements of the agency’s 2022 heavy-duty nitrogen oxide (NOx) emissions rule while retaining the underlying emissions standards. Among the most significant changes for the bus industry is a proposal to eliminate emissions-related engine derates — automatic speed restrictions triggered when diesel exhaust fluid (DEF) systems malfunction.

CALSTART, a nonprofit focused on advancing clean transportation technologies, said maintaining the underlying NOx emissions standards is positive but warned that relaxing implementation requirements could create uncertainty for manufacturers and reduce emissions benefits over time.

“EPA’s decision to retain the current stringency of the NOx emissions program for heavy-duty vehicles is a strong testament to the hard work the agency undertook in 2022,” said CALSTART President/CEO Michael Berube. “Unfortunately, EPA’s latest proposed changes risk introducing confusion and additional market uncertainty for the heavy-duty truck and engine manufacturers and the fleets that depend on reliable vehicle operation.”

Coverage also seen in Commercial Carrier Journal, Truck News, School Bus Fleet, and The Trucker.