Plans were made to install a Rankine cycle power system in a 25 - passenger city bus. Tests were conducted on a conventionally powered bus to establish baseline emissions with which the Rankine system emissions could be compared. The test vehicle was a Twin Coach 25 - passenger city bus powered by a 413 C.I.D. Chrysler V-8 engine burning gasoline. The engine was mounted in the rear and drove the rear wheels through an automatic transmission. The engine had positive crankcase ventilation. For these tests a simulated inertia weight of 5,500 lbs., the maximum available on the Clayton two-roll dynamometer, was used. The report describes the test procedures and the results in detail. It was concluded that the value of the emissions data is suspect because significant test conditions were not as they should have been. These conditions are described.