The Environmental Protection Agency last week formally proposed its plan to improve air quality by fortifying standards for diesel fuel and the heavy-duty truck and bus engines that burn the fuel.
The details of the final rules, released Dec. 21, contained few changes from what EPA had proposed in May for engine manufacturers and the oil industry. While the engine makers welcomed the changes, the oil industry was openly critical.
EPA will require that 80% of the diesel fuel produced for on-road use after July 1, 2006, contain no more than 15 parts per million of sulfur, compared with 500 ppm today, a 97% reduction. By 2010, all diesel will have to meet the new standard.
The reduced-sulfur fuel is intended to help 2007 model-year engines achieve lower soot and smog emissions. The higher-sulfur fuel would be earmarked for older trucks and buses.
For the full story, see the Dec. 25 print edition of Transport Topics. .