In accordance with embodiments of the present invention, a system is provided comprising an oxygen-enrichment reverse osmosis unit coupled to an intake of an internal combustion engine. Ambient air is supplied to the reverse osmosis unit via an ambient-air inlet and oxygen-enriched air is output via an oxygen-enriched outlet. The oxygen-enriched outlet is coupled to the intake of a combustion chamber of the internal combustion engine. Providing oxygen-enriched air relative to ambient air to the internal combustion engine allows for reducing the size of the combustion chamber while providing equivalent power, resulting in a smaller engine. At the same time, the smaller engine saves consumption of fuel due to lower engine weight and more complete combustion. The smaller engine is also cheaper to build because it requires less material for fabrication.