Many drivers using cars with low frequency often wonder if the car has not run enough recommended kilometers and does not need to change engine oil or not? According to a car repair technician at Ninety Eight Auto (Cat Lai ward, Ho Chi Minh City), in addition to the operating distance, the usage time is also an important factor in determining the time to change the oil.
In the current market, semi-synthetic oil is still a popular type on many popular car lines. Depending on the type of oil, manufacturer's recommendations and usage conditions, the oil replacement cycle usually ranges from about 5,000 - 8,000 km. However, actual operating conditions rarely reach the ideal level.
Cars frequently moving in urban areas, traffic jams, continuous acceleration and deceleration, running short distances or operating in high temperature environments will cause engine oil to degrade faster.
Therefore, many technicians recommend replacing semi-synthetic oil after about 5,000 km in common usage conditions in Vietnam to ensure lubrication and engine protection.
For total synthetic oil, many manufacturers announce that the oil change cycle can be up to 15,000 km or higher in standard conditions. However, when operating in practice, especially in crowded traffic conditions and hot and humid climates, many technicians recommend oil changes at about 10,000-12,000 km or as recommended by manufacturers if they arrive earlier.
According to Ninety Eight Auto technicians, changing the oil earlier than recommended generally does not harm the engine, but can increase maintenance costs if the oil is still within the limit of use. Conversely, changing the oil too late can cause the oil to gradually lose its lubrication, cleaning and protection capabilities for internal engine parts.
For cars with little use, the mileage is no longer the only criterion to determine the oil change time. If after a long time the car still does not meet the prescribed mileage, the car owner should still replace the oil according to the cycle of time recommended by the manufacturer.
Usually, semi-synthetic oil should be replaced after about 6-12 months, while total synthetic oil is about 12 months, depending on the type of oil, usage conditions and manufacturer instructions. For vehicles that frequently travel only short distances or operate in harsh conditions, technicians may recommend a earlier replacement.
The reason is that after being poured into the engine, the oil is no longer in a closed storage state but continuously comes into contact with oxygen, moisture and products generated during fuel combustion. Over time, the oil will be oxidized, additives gradually reduce their effects, and can also absorb moisture from the environment.
For slow-moving vehicles, the engine does not regularly reach working temperature, so the amount of water vapor accumulated in the oil is difficult to completely eliminate. This causes oil to degrade over time even if the mileage is still low, reducing lubrication and engine protection efficiency.
Technicians recommend that car owners should simultaneously comply with both criteria: kilometers and time, applying which milestone comes first. Regularly changing the oil according to the manufacturer's recommendations will help the engine operate stably, extend its lifespan and limit repair costs incurred during use.
