Alternative Automobile Engines.

A technology assessment of various heat engines for automobile propulsion is presented covering: the spark ignition (Otto) engine; the compression ignition (diesel) engine; the vapor cycle (Rankine) engine; the Stirling engine; and the open and closed Brayton cycle (gas turbines) engines. Comparative data given include temperature ratio, thermal efficiency, power to mass ratio, exhaust emissions, and manufacturing cost. The defects of alternative engines to the spark ignition engine are clearer than their virtues, and the choice of a single best alternative is complex. Government policies with respect to the automotive industry are discussed. (PMA)