대체 이런 거 왜 하지? 싶었던 엔진 플러싱...생각보다 괜찮은데요?

Additional Information If you change your engine oil frequently, this is a task you'll never need again. In the long run, even if your car's condition is poor, I believe it will gradually improve if you just change the oil filter and engine oil frequently. I used 3L of GS Caltex flushing fluid, which costs about 3,500 won, and it was fine. Unfortunately, my car's oil is well-maintained, so I don't think I'll need to use it again.