Palio, how many kilometers does it take to clean the accelerator and add oil?

Clean the throttle, replace the spark plug, what else to clean the oil circuit, clean the water tank and add fuel additives? I've been driving for ten years, and two cars are still directly scrapped. I have never done these projects, unless you want to send two dollars to the repair shop. Many things in the car are not consumables, so you don't have to touch them for life if there is no problem. If something goes wrong, the repair shop doesn't mean to let you wash or replace it, but just check the belt wear and tensioner during the usual maintenance. It is best to change the oil every 5,000 kilometers, 10000 check the brake pads, 20,000 water tanks for gearbox oil, 50,000 four-wheel bearings for belt oil and 80,000 brake oil. Usually pay more attention to tire pressure, water temperature and engine sound. It is best to install a water thermometer.