When to Change Engine Oil?

[Sawyer]

There is no fixed interval for changing engine oil, as it depends on actual driving conditions and vehicle status. Different types of engine oil have different replacement cycles. The details are as follows: 1. Engine oil can be divided into mineral oil, semi-synthetic oil, and full-synthetic oil. If mineral oil is used, it is generally recommended to change it every six months or around 5,000 kilometers; if semi-synthetic oil is used, change it every 7-8 months or around 7,500 kilometers; if full-synthetic oil is used, it can be changed after one year or around 10,000 kilometers. 2. For new cars, it is best to change the engine oil around 2,500 kilometers to better remove metal debris generated during the engine break-in period. Vehicles with low mileage can change the oil once a year, provided synthetic oil is used. For vehicles frequently driven or used in low-temperature conditions, it is recommended to change the engine oil and oil filter every 5,000-7,000 kilometers for optimal performance.

[JamesMarie]

Regarding oil changes, I personally believe it should be determined based on driving conditions. The most common practice is to follow the mileage recommendations in the vehicle manual, where regular cars typically require an oil change every 5,000 to 10,000 kilometers. However, since I often commute in city traffic with frequent stops, the engine runs at low RPMs, causing the oil to degrade faster, so I usually change it every 5,000 kilometers. On the other hand, my cousin, who drives mostly long-distance highways, can extend the interval to 8,000 kilometers because the engine load is more consistent. If the oil appears black or has a burnt smell, it should be changed immediately regardless of mileage. In winter, when temperatures drop to -20°C, it’s important to consider low-temperature fluidity, making 0W-grade full synthetic oil more suitable. Don’t just focus on mileage—time intervals matter too. Even if the car isn’t driven, the oil should be changed every six months due to oxidation and degradation.

[NoahAnn]

My previous car had run 150,000 kilometers with over a dozen oil changes, and I've summarized a few key lessons. First, always refer to the official recommendations in the vehicle manual—Japanese cars typically require changes every 5,000 km, while German cars often go up to 10,000 km. Second, consider the oil type: mineral oil starts degrading around 4,000 km, semi-synthetic around 6,000 km, and full synthetic can last beyond 8,000 km. In stop-and-go traffic with frequent starts, reduce the interval by 20%, whereas highway cruising allows for extended intervals. A handy tip: during maintenance, ask the mechanic to check the dipstick for oil level and viscosity. If the oil is below the minimum mark or unusually thin, it’s time for a change. Forgetting an oil change leads to louder engine noise and increased fuel consumption—don’t ignore these warning signs.

[Michael]

Oil change intervals depend on three key factors: mileage, time, and driving conditions. My recommendation is to track monthly mileage - regular family cars should change oil around 7,000 km, but never exceed 12 months. Special note for modified car enthusiasts: Vehicles with ECU tuning or turbochargers run hotter engines, suggesting 30% shorter change intervals. A friend's performance car once suffered cylinder scoring from degraded oil, costing over 8,000 RMB in repairs. Northern drivers should schedule winter oil changes before freezing temperatures, switching to low-temperature oil. Always supervise mechanics during draining - I once caught an apprentice adding new oil without fully removing old oil, which reduces lubrication effectiveness when mixed.

[RonanLee]

The most practical approach is to determine the oil change interval based on its condition. I make it a habit to check the dipstick every two weeks: pull it out, wipe it clean, reinsert it, and as long as the oil level is between the upper and lower marks, it's fine. However, transparency is even more important. Fresh oil is amber and clear; when it turns dark brown, it's time to prepare for a change. Fully synthetic oil has a stable molecular structure and can last up to 12,000 kilometers, but after continuous uphill driving on mountain roads, an earlier change is advisable. Turbocharged vehicle owners, take note: turbo bearings can exceed 300 degrees Celsius, causing oil to carbonize easily, so changing it every 6,000 kilometers is safer. Additionally, vehicles frequently used for short trips are particularly prone to carbon buildup, so shortening the oil change interval is recommended. Forgot to mention manual transmission cars—while engine oil needs frequent changes, gear oil only requires replacement every 100,000 kilometers.