In the last decade, heavy-duty truck emissions have been reduced some 95 percent and, specifically, diesel particulate matter and nitrogen oxides. As a reference point, today it takes about 60 big rigs to produce the emission levels of one unit built on the late 80s. Rarely do we see a truck engine smoking today. At last October’s Green Fleet Conference, a panel of experts talked about the misconceptions that are often floated regarding alternative fuels.