Field Trials of Ethanol in Transit Buses

Regina Transit has operated two ethanol fuelled buses since March 1991. On-road performance and operator acceptance has been good, with few maintenance problems. Volumetric fuel consumption is close to twice that of similar diesel buses. In comparison to a similar diesel bus, emissions tests on a chassis dynamometer have shown reductions in NO_x and Particulate emissions over four typical test cycles. However, in three cases CO emissions were higher. OMHCE emissions were consistently higher, largely due to the level of unburned ethanol in the exhaust. The buses were not fitted with catalytic converters at the time of testing.