Oil should refer to fuel. An internal combustion engine is a machine that converts the chemical energy of fuel into mechanical energy. Check the amount of oil in the fuel tank and whether the pipeline is smooth. Check whether there are leaks, etc.
Water is the cooling water of the internal combustion engine, which cools the heat of the cooling system of the internal combustion engine through the radiator.
In addition, the lubrication system of the internal combustion engine also includes engine oil to ensure the lubrication of moving parts.