Pumping oil should be drained cleanly than loose oil bottom screws. Because the pumping oil is pumped by compressed air, about 80% of the old engine oil can be pumped out. And the old oil is drained by the loosing screw, gravity is used to drain the old oil, some small oil holes, the old oil in the oil passage cannot be released by gravity.

Clean the oil when replacing the oil. Steps to replace the oil:
1. The vehicle starts, the water temperature reaches the normal driving temperature, and the engine is turned off. The purpose of warming up the car before changing the oil is to allow the oil to flow fully, so that it is easier to take out the impurities, and then use a jack to jack up the car and tighten the handbrake;
2. Loosen the bolt on the side of the oil pan with the tool provided with the vehicle to release the engine oil. Note that the old oil should be collected in a container to avoid environmental pollution. When the oil is drained, install the oil drain plug. Be careful not to tighten it too tightly to avoid damage to the oil pan. When replacing the oil, the oil filter is generally replaced;
3. Loosen the filter element with an oil filter element wrench, then unscrew it by hand, apply new oil to the oil seal of the new filter element, and then manually install the new oil filter element, and finally tighten it with a tool;
4. Pour the oil into the oil filler port. Be careful not to pour it outside the engine. I really think it can be used as a funnel depending on the situation. After the oil is filled, just check if there is any leakage.