Over the last 10 years, emissions from heavy-duty diesel trucks and buses have been reduced by 99% for nitrogen oxides – an ozone precursor – and by 98% for particulate emissions, according to Allen Schaeffer, executive director of the Diesel Technology Forum.
‘Consider that it would take 60 of today's clean diesel trucks to equal the same emissions from one pre-1988 truck,’ Schaeffer says. ‘This remarkable 60-to-1 ratio is a vivid indicator of the remarkable advances in clean diesel technology.’
In addition, the new ultra-low sulfur diesel fuel, which has been required since 2010, has reduced sulfur emissions by 97% – from 500 PM to 15 PM, according to Schaeffer.
‘These historic environmental improvements take an even more important significance when you consider that over 80 percent of all freight in the U.S. is moved by diesel-powered trucks, railroads and marine vessels,’ he notes. ‘With an estimated 11 million older diesel engines still in operation, it's vital the federal, state and local governments continue programs like the Diesel Emissions Reduction Act to modernize and upgrade the older buses, trucks, tractors and marine vessels.’