When the main and auxiliary oil tanks of JH6 are filled with oil of the same grade, they can be switched to another oil tank at any time. Just switch the switching valve to the main oil tank to work. At this time, the indicator light on the switch is on, indicating that the engine is supplied with oil from the main oil tank. When the main fuel tank is switched to the auxiliary fuel tank, it will be delayed for 2 minutes, and the auxiliary fuel tank will not be switched to the main fuel tank. This is the fuel-saving technology for liberating JH6 system.