The system worked by disabling the valves on cylinders number 1 and 4 at speeds below , at idling, and while decelerating. Fuel consumption figures were generally about 20 percent improved over the regular 4G12 engine. Period sources, however, complained about the engine running very roughly while in two-cylinder mode, despite special engine mounts with hydraulic damping. Other efforts taken to minimize vibrations and harshness included a section of flexible exhaust pipe, not operating the system until the coolant temperature reached 70C, and a 70 percent heavier flywheel. Mitsubishi's effort remained short-lived, mainly because of a lack of response from car buyers.