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
School buses in Ft. Wayne, Indiana, and St. Louis were sidelined Monday when the biodiesel may have clogged up fuel lines. About 25 percent of the buses in Fort Wayne area were affected. Officials say they run on B20, which is a mix of 20 percent biodiesel and 80 percent premium diesel fuel. The problems may not be entirely the fault of biodiesel. Officials also said some buses that run on 100 percent diesel fuel in other districts also failed.