Through the clean air act and other various federal and state legislation, fleets are facing greater pressures to use alternate fuels. This is not because alternate fuels are so desireable, but that they are potentially the fuels, used with recent engine developments, which can meet the future emission standards of the E.P.A.. These alternates are: liquified natural gas, compressed natural gas, methanol and ethanol. Currently there is no national or local publically available infrastructure system for the distribution of these fuels. Despite the weakness in the infrastructure system, alternate fuel usage seems certain to grow in the future.This paper will outline two micro-tests conducted in Chicago using biodiesel as an alternate fuel for in-service motorcoaches. This was an exploratory investigation to determine the effects of the fuel on the engine, the performance characteristics and the infrastructure requirements needed to use this fuel. However only a micro-test, the significance of this program cannot be overlooked. It is testing of this nature which proves biodiesel can be used as a feasible alternate for in-service diesel powered vehicles.