Combustion in Piston Engines presents the technique of pressure diagnostics to measure the fuel consumption in an engine cylinder and to monitor the operation of micro-electronic systems for its control. It provides a recipe for bridging the gap between the hydrocarbon-fed combustion technology of automotive powerplants of today and electro-magnetic technologies of the future. The author proposes and introduces a model for the design of a MECC (micro-electronically controlled combustion) systems to modulate combustion in engine cylinders. This system yields significant reduction in the formation of pollutants and the consumption of fuel, so that, eventually, emissions using any clean hydrocarbon fuel will be acceptable and gas mileage could be doubled.