Combustion and control variables: In figure 1 the four cycles of a gasoline engine are shown in a pressure/volume diagram. The mean engine torque results from the difference energy explained by the two closed areas in the figure. The large area describes the relation of pressure and volume during compression and combustion. The charge cycle is represented by the smaller area. For good efficiency the upper area should be as large as possible and the area below should be minimal (for a given gas quantity). The best possible efficiency in theory is represented by the constant-volume cycle (or Otto cycle) (
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.