This article described the characteristics of the liquid nitrogen engine’s ideal open cycle. Using two interconnecting strokes to achieve the power output can mitigate the trade off between high efficiency and the potential mechanical complexity of multiple cylinder engines. The total specific energy of the binary media (methane nitrogen) cycle system could be much higher than the unitary medium (liquid nitrogen) cycle system. By theoretical analysis, the reasonably acceptable driving range proved the feasibility of the liquid nitrogen engine used for supplying power for a lightweight car. This article described the characteristics of the liquid nitrogen engine’s ideal open cycle. Using two interconnected strokes to achieve the power output can mitigate the trade off between high efficiency and the potential mechanical complexity of multiple cylinder engines. The total specific energy of the binary media ( By theoretical analysis, the reasonably acceptable driving range proven the feasibility of the liquid nitrogen engine used for supplying power for a lightweight car.