Method of operating a compression ignition engine

Method of operating a compression engine on dimethylether containing fuel obtained by conversion of methanol primary fuel, comprising the steps of: (a) pressurising the primary methanol fuel in its liquid form to a final engine injection pressure; (b) preheating the pressurised primary fuel by heat contained in engine exhaust gas; (c) introducing and converting the primary fuel at injection temperature of the engine and the injection pressure to dimethylether containing fuel by contact with a methanol dehydration catalyst; and (d) injection the dimethylether containing fuel at the injection pressure and temperature into the engine.