Abstract: An electrolyser system produces combustion enhancing gas for communication with the intake of an internal combustion engine. An anode and a cathode are supported spaced apart from one another in a chamber filled with electrolytic solution with the cathode and the anode being nearest one another adjacent a bottom end of the chamber to concentrate the electrolysis activity adjacent the bottom end of the chamber. The electrolysis activity is therefore not significantly affected by varying levels of solution in the chamber. The anode comprises a plurality of independent units with respective independent power supplies. An amperage control selectively connects and disconnects the power supplies with the respective independent units of the anode for adjusting applied amperage across the solution and accordingly for varying the production rate of combustion enhancing gas responsive to engine demands.