When Should Car Engine Oil Be Changed?

[MacThomas]

Car engine oil change intervals depend on the type of oil: 1. Fully synthetic oil should be changed every 10,000 kilometers or 1 year; 2. Semi-synthetic oil should be changed every 7,500 kilometers or 7 to 8 months; 3. Mineral oil should be changed every 5,000 kilometers or 6 months. Precautions for changing car engine oil include: 1. Perform the change when the engine is warm to ensure thorough drainage of old oil; 2. Add new oil ensuring the correct quantity; 3. After adding oil, start the engine to check for leaks, then run the engine for 3 minutes to confirm the oil level reaches the normal mark.

[BrookeFitz]

I change the oil in my SUV every 8,000 kilometers or so. Last time, the technician at the 4S shop showed me the test paper—the oil had spread into a soy-sauce color, indicating the cleaning components were mostly depleted. Winters here are brutally cold, often hitting -20°C, so the mechanic specifically advised using 0W-20 grade oil for better cold-start fluidity. Once, when I left the car unused for three months during a business trip, the engine sounded noticeably rough upon starting. Long-term parking actually damages the oil more than driving 5,000 km, so I’ve made it a habit to change the oil if the car sits idle for over two months. Many new cars now display a wrench icon as a reminder, but experience tells me not to rely solely on it.

[DiEvelyn]

Over the years of driving for ride-hailing, I've thoroughly researched engine oil. Covering over 300 kilometers daily, I stick to oil changes every 6,000 to 7,000 kilometers. During traffic jams, I frequently check the oil temperature—if it exceeds 110 degrees Celsius for three consecutive days, I head for maintenance early. Once, hearing a ticking sound from the engine bay, I immediately checked the dipstick and found metal shavings. The mechanic warned that waiting another half-month could have led to a major overhaul. Now, I make it a monthly ritual to inspect the oil's condition—normally it's a clear caramel color. If it turns black with a gasoline smell, it's likely diluted. At gas stations, I've seen turbocharged car owners opt for cheap mineral oil, only to have sludge clog the oil pan after 5,000 kilometers—truly not worth the savings.

[LeEliana]

Last month before taking my daughter on a road trip, I specifically checked the maintenance manual to confirm the oil change interval. The manual states 10,000 km, but the sticker from the 4S shop shows 7,500 km. After consulting a senior technician, I learned the key factor is the API certification rating - my car uses SP-grade full synthetic oil which lasts longer than the older SN-grade. Since I mostly drive short trips to pick up my daughter, the technician said the oil's mileage lifespan should be reduced by 30%. Now I change it every eight months for better protection. Once during maintenance, I saw the drained oil looking like asphalt, and the mechanic said its lubrication effectiveness was down to just 30% in that condition.