Abstract: An exhaust gas turbine powered electric generating system for supplying electrical loads on a motor vehicle. The inlet of the gas turbine is supplied with the exhaust gas of an internal combustion engine. The effective turbine inlet area is controlled by a valve which is adjusted as a function of the output current of the generator. As generator output current increases the valve is adjusted to decrease turbine inlet area thereby increasing engine back pressure which tends to slow the engine down. An idle speed control is provided which in response to engine slow-down increases the amount of air and fuel supplied to the engine to thereby increase the exhaust gas mass flow supplied to the turbine.