A fuel for a combustion engine includes from about 95.0% to about 99.9% by weight of a liquid water/alcohol mixture, in which water makes up from about 1% to about 15% by weight of the mixture, and from about 0.01% to about 5.0% by weight of an alkyl nitrate.

The present disclosure is directed to fuel compositions comprising a polar based continuous phase comprising a liquid ammonia with a concentration greater than about 81% by v/v of total polar phase; and a non-polar based discontinuous phase comprising one or more of a frozen hydrocarbon, a viscous liquid hydrocarbon, and a liquefied volatile hydrocarbon, wherein the fuel composition has a droplet size ranging from about 100 nm to about 250 m. Further, the disclosure provides for systems and methods for using the fuel compositions.