The amount of lubricating oil should be controlled between the upper and lower scale lines of the oil dipstick. Because too much lubricating oil will escape from the gap between the cylinder and the piston into the combustion chamber and burn to form carbon deposits. These coke deposits will increase the compression ratio of the engine and increase the tendency of knocking. The coke deposits in the cylinder are red hot and easily cause pre-ignition. If they fall into the cylinder, they will aggravate the wear of the cylinder and piston, and will also accelerate the pollution of the lubricating oil. Secondly, too much lubricating oil increases the stirring resistance of the crankshaft connecting rod and increases fuel consumption.
Misunderstanding 2: When the lubricating oil turns black, it is time to change the oil
This understanding is not comprehensive. For lubricating oil without detergent and dispersant, the darkening of the color is indeed a sign that the oil has been seriously deteriorated, but the lubricating oil used in modern cars generally has a detergent and decomposer. This detergent will wash off the rubber film and black carbon deposits adhering to the piston and disperse them in the oil to reduce the generation of high-temperature deposits in the engine. Therefore, the color of the lubricating oil is likely to turn black after a period of use, but at this time The oil has not completely deteriorated.
Misunderstanding 3: Lubricating oil is often added and not changed
It is correct to check the lubricating oil frequently, but only supplementing without replacing it can only make up for the lack of oil quantity, but cannot fully compensate for the loss of lubricating oil performance. During the use of lubricating oil, the quality will gradually decline due to pollution, oxidation and other reasons, and at the same time there will be some consumption, which reduces the quantity.
Misunderstanding 4: Additives are useful
Real high-quality lubricants are finished products with a variety of engine protection functions. The formula already contains a variety of additives, including anti-wear agents, and the lubricants pay attention to the balance of the formula to ensure the full performance of various performances. Adding other additives by oneself will not only not bring additional protection to the vehicle, but it will easily react with the chemical substances in the engine oil, resulting in a decline in the overall performance of the engine oil.