The Environmental Protection Agency (EPA) now requires U.S. refineries
to begin making ultra-low-sulfur diesel (ULSD), which has 97 percent
less sulfur than ordinary diesel fuel. The rule requires 80 percent of
the diesel produced for highway-use be ULSD. By October 15, all stations
selling diesel will be required to sell ULSD.
Diesel vehicles emit about 10 percent less pollution running on
ULSD. Heavy-duty trucks and buses with new clean-diesel engines are due
in early 2007. They will cut soot and nitrous-oxide emissions by 90