The National Renewable Energy Laboratory (NREL) has just completed the first year of a study comparing St. Louis transit buses running on B20 biodiesel and ultra-low sulfur diesel (ULSD). Surprisingly the B20 buses actually had slightly lower average mileage than the ULSD fleet, 3.52 vs 3.58 mpg. The new study is the first to examine B20 use on buses equipped with exhaust gas recirculation systems. The EGR helps to reduce NOx emissions. Fifteen identical buses were examined in the study with
When most people think of hybrid vehicles, the Prius, or other similar petrol-electric passenger vehicles come to mind. But there is another hybrid revolution under way in the stop-start world of transit buses; hybrid diesel-electrics. Around 20 percent of all transit buses are now hybrid diesel-electric models. In comparison to hybrids making up just 1.5 percent of U.S. car and light-truck sales.