The current "freeze" on corporate average fuel economy (CAFE) standards may be nearing its end with the Clinton administration and the U.S. Dept. of Transportation battling for higher fuel economy standards across the board. The booming light truck, minivan and sport/utility vehicle (SUV) segment has been held stationary at the 20.7 mpg (11.4L/100 km) standard since 1995. But the U.S. House seems to be just a tad more interested in raising CAFE standards as light trucks, SUVs and minivans are on pace to outsell passenger cars for the first time in history. Even as stiffer CAFE regulations are being considered, the Environmental Protection Agency (EPA) proposes new regulations that dictate a drastic 95% reduction in emissions from heavy-duty diesel trucks. A prime component of the proposed legislation requires diesel fuel sulfur levels to be slashed from the current average of about 500 parts per million (ppm) to 15 ppm by 2006. From there, heavy-duty diesel engine makers must begin to adopt technology that will reduce the rest of the emissions, primarily oxides of nitrogen (NOx) and particulates.