EPA’s New NOx Reduction Proposal Debated at Hearing


A new proposed standard by the US EPA, announced March 28, would significantly reduce emissions of smog- and soot-forming nitrogen oxides from heavy-duty gasoline and diesel engines, and set more stringent greenhouse gas standards for certain commercial vehicle categories, reports Transport Topics.

It’s been more than 20 years since EPA issued a NOx rule.

The proposal offers two options. Option 1 calls for basically a 0.035 gram per brake horsepower-hour for model years 2027-2030, stepping down to an 0.02 gram per brake horsepower-hour for 2031-plus. Option 2 calls for an 0.05 gram per brake horsepower-hour for model year 2027-plus.

“EMA’s members support the adoption of stringent, single step, reduced NOx standard, a low-load cycle, enhanced in-use test procedures, and cost-effective improvements to extend an emissions warranty in useful life periods,” said Jed Mandel, president of the Truck and Engine Manufacturers Association. “We also support a program that can be a successful bridge to a zero-emission commercial vehicle future.”

Still, Mandel questioned the approaches suggested. “EPA’s proposed rule in its current form is not technically feasible, cost effective, or customer acceptable,” the group said. “As a result, critical fleet turnover will be delayed, and customers will keep their higher emitting trucks longer. Further, a poorly designed final rule will cause market disruptions, will delay or undermine the ability of manufacturers to recoup their investment in developing compliant technologies.”

By comparison, California environmental regulators told EPA they were dismayed with the proposed rule because it does not go far enough in regulating NOx, or create an effective pathway to a national electric truck future.

“Today’s generation of diesel technology has been a success story, having achieved over a 98% reduction in nitrogen oxides and particulate matter over previous generations,” said Allen Schaeffer, executive director of the Diesel Technology Forum. “The last thing anyone wants is for truckers to stop buying new trucks because they are too expensive, too unpredictable or too complex. Above all else, this proposed rule must enable continued investment in the next generation of diesel technology.”

Full article here.

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