Liquid fuel is burned by feeding a mixture of a liquid fuel (such as petrol, diesel oil or fuel oil) together with liquid fuel which has been pre-gasified by rapid heating into a combustion zone. The combustion zone may be a furnace or internal combustion engine. The liquid fuel is gasified by contact with a hot body. An internal combustion engine comprises a heated chamber (26) having a heater (28), an air inlet (16) and a fuel inlet (20). The mixture of gasified fuel and air is then introduced into the inlet manifold (4) of the engine. Atomised liquid fuel and air is also inducted into the engine in conventional manner, such as via carburettor (8).
