UMA to EPA: Consider revising derate regulations

The United Motorcoach Association is asking the Environmental Protection Agency to consider revising derate regulations before issuing 2027 emission standards because of unintended consequences for the industry. 

The UMA filed May 16 in response to the EPA’s proposed rule, Control of Air Pollution from New Motor Vehicles: Heavy-Duty Engine and Vehicle Standards.

The EPA is proposing a rule targeted at reducing air pollution from heavy-duty vehicle engines in model year 2027. If adopted as proposed, the rule would change the heavy-duty emission control program, including standards, test procedures, useful life, warranty, etc., to further reduce the air quality impacts of heavy-duty engines under various operating conditions over an extended period of the operational life of heavy-duty vehicle engines.

Comments principally focused on the current inducement challenges, while UMA also asked the agency to consider how diverting financial resources from rapidly developing safety technologies to achieve the next level of nitrogen oxide reductions will impact costs when compared to the negative outcomes of crashes.  

Unintended consequences

“There are limits the consumers of bus and motorcoach services can absorb, providers will be less likely to adopt safety technologies,” UMA stated in comments. “EPA must consider the unintended consequences of displacing safety technologies and the subsequent adverse cost of bodily injury, property damage and fatalities when mandating additional engine technologies.”

UMA largely applauded EPA’s approach to restricting the inducements to issues related to low- or poor-quality diesel emissions fluid and tampering. The agency also proposes better diagrams and instructions from manufacturers.

The agency also proposed that codes associated with inducements and diesel particulate filter engine derates would be displayed on the dashboard or read with a generic scan tool.

The EPA proposed rule suggests four levels of derating, with a final inducement speed of 50 mph. UMA asked the agency to consider a slightly longer period (96-hours) utilizing five stages.

The UMA comments, hundreds of other public comments, and the proposed rule can be viewed at

Ken Presley is United Motorcoach Association’s Vice President, Legislative & Regulatory Affairs & Industry Relations, and Chief Operations Officer. 


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