Pour a bottle of detergent before changing the oil, let the engine run for a while, and then let the oil out. This is the way to clean the engine in 4S shop. This is to maintain the engine, which is very beneficial to prolong the service life. The engine is the heart of a car. Only by maintaining the "heart" can we better serve the owners.
It's no use adding detergent to the engine, it's just a gimmick for 4S stores to charge. No matter how high the purity of gasoline is, it will also produce carbon deposit. When encountering traffic jams, insufficient combustion, or violent driving, the speed of carbon deposition will accelerate. Carbon deposits exist in intake valves, spark plugs, pistons, exhaust pipes and other parts.
It is not enough to clean up all the carbon deposits in it by adding a bottle of detergent, especially for engines that have started to burn oil, which is meaningless. It may also cause cars that have not started burning oil to burn oil soon. Cleaning agent can peel off some thick sludge and dilute it in engine oil. When the engine is running, it circulates everywhere inside, which is easy to cause problems in some narrow places and cause congestion. The most common is the inner ring of oil circuit, which is easy to cause cylinder pulling over time.