A GT-225 automotive gas turbine has been tested for particulate emissions at steady speeds on a chassis dynamometer. The object was to develop test criteria and data sufficient to enable the design of a facility for transient particulate testing of gas turbines.The steady-speed test rig is described, along with the instrumentation, test methods, data reduction, and methods of sample analysis. The need for cooling the exhaust gases by dilution, analogous to diesel particulate tests, is also shown.Steady-speed test data are presented to show the effects of vehicle speed or load, engine cycle temperature, six different fuels, and two different combustors on the particulate emissions. Generally, the steady-speed particulate emissions were extremely low, with particulate emissions indexes less than 0.01 g/kg fuel at normal operating conditions. Most particles are less than 0.1 μm in diameter, and roughly 9096 of the mass is sulfate.These results should not be extended to other gas turbine engines. In fact, they may not fully characterize the GT-225 engine, since only one-half of the exhaust was examined.