Which step should be avoided the most when changing engine oil in 3 steps?

Choosing the wrong engine oil: When choosing engine oil, it is essential to strictly follow the oil grade specified in the car's user manual. If there is no engine oil of the same grade on the market, a higher grade of engine oil can be chosen, but it is absolutely forbidden to use a lower grade of engine oil as a substitute. At the same time, the viscosity of the engine oil is also a factor to be considered. Do not blindly pursue high prices and ignore applicability. Negligence in the oil drain and inspection process: After the technician opens the oil pan screw or the oil filter to drain the waste oil, it is necessary to replace the oil pan screw with a new screw washer and tighten it. Before installing a new oil filter, carefully check whether the rubber sealing ring of the old filter has been removed at the same time to avoid oil leakage caused by the overlap of the new and old sealing rings. In addition, a layer of oil film should be applied to the rubber sealing ring of the new oil filter to facilitate lubrication during installation and prevent damage to the sealing ring. Inaccurate oil addition: Add oil according to the vehicle's displacement, avoiding too much or too little. Excessive engine oil can lead to power loss inside the engine and even cause oil burning problems. Insufficient engine oil will cause the bearings and journal inside the engine to wear out more rapidly due to inadequate lubrication. In severe cases, it may lead to serious accidents. Therefore, when adding engine oil, make sure the oil level is between the upper and lower marks on the dipstick