Advancements in clean diesel technology are highlighted in a new study by the University of California-Riverside that found commercially cooked hamburgers emit more particulate matter than 2007-2010 model year clean diesel trucks.
The University of California-Riverside study was funded by the South Coast Air Quality Management District and the San Joaquin Valley Air Pollution Control District.
"While the primary focus of this new study was on emissions from commercial charbroilers, this comparison clearly illustrates the significant improvements from clean diesel technology on California's air quality. In fact, the study also found that the particulate matter inventory from commercial cooking is more than double the inventory from heavy-duty diesel trucks." said Allen Schaeffer, the Executive Director of the Diesel Technology Forum.
Bill Welch, principle engineer at UC-Riverside said an 18-wheeler diesel engine truck would have to drive 143 miles on the freeway to put out the same mass of particulates as a single charbroiled hamburger patty.
Schaeffer said the comparison was "extremely unusual."
"Generally, clean diesels are matched up against natural gas, hybrids or electric vehicles for emissions or fuel efficiency tests. This is the first time we've gone head-to-head against fast food," Schaeffer said.
He added that the majority of particulate emissions, in California, come from brake and tire wear, with diesel emissions making up small and declining fraction.
Schaeffer explained that the switch to ultra-low sulfur diesel fuel in 2006 spurred the emission reduction. As a result of the switch, he said, sulfur emissions have been reduced by 97%.
"In the United States, emissions from heavy-duty diesel trucks and buses have been reduced by 99% for nitrogen oxides (NOx) - an ozone precursor - and particulate emissions," Schaeffer said. "Across the U.S., emissions of particulate matter from diesel engines make up less than 6% of all particulate emissions."
Schaeffer added that it takes about 60 of trucks made with todays technology to equal the emissions of one truck made in 1988.
Farm tractors are also moving toward near-zero emissions for particulate matter, he said.