When is the right time to change car engine oil?
2 Answers
According to the type of engine oil, the replacement intervals vary. Generally, mineral oil needs to be replaced every 5,000 kilometers; semi-synthetic oil should be changed approximately every 8,000 kilometers or 8 months; while full-synthetic oil requires replacement around every 10,000 kilometers or one year. Below are the key functions of engine oil: 1. Lubrication: Maintains viscosity between cylinders and pistons for proper operation, reduces friction between components, and minimizes wear. 2. Cooling: Assists the cooling system in lowering the internal temperature of the engine to some extent. 3. Cleaning: Removes sludge, carbon deposits, and other impurities attached to engine parts, keeping the environment clean. 4. Sealing: Seals gases within the engine pistons and piston rings, reducing the entry of external contaminants.
As someone who commutes by car year-round, I believe the timing for oil changes should be flexible. Manuals typically recommend changing every 5,000 to 7,500 miles or every 6 months, but my experience suggests considering driving habits. If you frequently drive in congested urban areas with repeated engine starts and stops, oil contaminants accumulate faster, so I change around 5,000 miles. For long-distance highway driving with smooth operation, synthetic oil performs better under high temperatures and can last up to 7,500 or even 10,000 miles. Never wait just for the dashboard warning light—regularly check the dipstick yourself. If the oil turns black or the level drops, act promptly to avoid increased engine friction and reduced lifespan. Climate also matters: in hot regions, oil thins and provides less lubrication, while in cold areas, it thickens and slows cold starts. Early checks can prevent major repairs. An oil change is a small expense compared to costly repairs, so I maintain this habit monthly.
