Abstract: In combusting fuel in an internal combustion engine with a fuel combustion system having a fuel tank, a fuel injecting system for injecting fuel into a cylinder section and a fuel path for providing fluid communication between the fuel tank and the fuel injecting system, a magnetic field is applied, by means of a magnetic field applying device, to the fuel flowing from the fuel tank to the fuel injecting system through the fuel path. The magnetic field applying device is provided either along the fuel path or in the fuel injecting system.