This contribution presents an overview over the use of ammonia as a fuel for internal combustion engines either as pure substance or in combination with ignition promotors. The concept of a two-component fuel mixture system consisting of ammonia and an organic solvent for storage of ammonia and as combustion enhancer is developed. Requirements toward a solvent for its use in an ammonia/solvent fuel system in internal combustion engines are summarized. Employing the quantum chemical COSMO-RS theory, a broad variety of hydrocarbons with different functional groups and carbon chain lengths as well as solvents already reported as alternative fuels in the literature are systematically screened. The resulting candidates are rated in a multicriterial approach, accounting for physical properties and phase equilibrium behavior, combustion characteristics, as well as operational properties.