Oil change based on mileage only: Common user mistake

If gasoline is considered "food", then lubricating oil is like the "blood" of the engine. In the composition of lubricating oil, there are additives that ensure cleaning, anti-chemical corrosion, and anti-foaming properties.

During combustion, fuel generates carbon deposits and dust that adhere to the engine. Lubricating oil will disperse these deposits and soot into small molecules and retain them in the oil. After a period of use, the residue content exceeds the allowable threshold and can adhere back to the engine.

Therefore, changing the lubricating oil is very necessary, but determining when to change it makes many people wonder.

Lubricating oil is an essential component inside the engine.Image:Small Frog.

Mr. Do Duy Duc - Director of Duy Duc Workshop believes that currently, car users in Vietnam are forming some incorrect concepts and habits when replacing engine lubricating oil.

The first habit is to change the engine oil mechanically according to the number of kilometers operated. Changing the engine lubricating oil after how many kilometers of use, seems to be a simple question. However, the specific number, 3,000km, 5,000km, or 10,000km... depends on many factors.

Firstly, the oil change depends on the type of lubricating oil according to the vehicle manufacturer's standards. For example, the Mazda CX-5 2.0 AT 2016 standard version of the manufacturer uses Castrol 5W30 SN oil, for an engine in good condition, this oil has a replacement period of 5,000 km of operation. Therefore, with the engine of this car, pouring in oil with an index of 0W40 is not correct in terms of parameters, not to mention which brand of 0W40 oil and how many km it can be used before it needs to be replaced.

Second, it also depends on the actual condition of the engine. Also taking the above example for the Mazda CX-5, when first put into use, the periodic oil change is 5,000 km. However, due to the operating characteristics, or after many years of use, with hundreds of thousands of kilometers of operation, the internal parts of the engine have larger gaps, are more worn, so the oil needs to be replaced with a shorter period of operating kilometers than the original factory specifications of the car.

Third, oil changes depend on operating conditions. A car that is frequently operated in traffic jams, flooded areas or has short stops, etc., will need to change its oil at shorter mileage intervals than a car that is operated in better conditions.

Cars flooded should change oil immediately.

Changing the oil only based on the number of kilometers traveled, without paying attention to the date is also a bad habit. Because although the car runs less, the lubricating oil stored in the engine will degrade over time, you can not only look at the number of kilometers to change the oil.

And according to recommendations, 5W and 10W multi-grade oils should be replaced after 3 months of use, regardless of whether they are used little or a lot. 0W oils should be replaced after 6-12 months depending on the quality of additives in that oil.

The third bad habit is to replace the engine oil at home or at non-professional facilities. Many car owners tend to replace the engine oil at home or at car washes, which can easily lead to risks such as leaking drain plugs, opening the wrong drain plug, adding the wrong type of oil or adding the wrong amount of oil.

Next is the use of additives of unknown origin. Many vehicle owners add unverified additives of unknown origin into lubricating oil to meet their expectations, such as cleaning or descaling. If users do not research carefully, additives that are not compatible with the lubricating oil in use can upset the chemical balance in the oil and reduce the performance of the lubricating oil.

Not changing the oil filter can also damage the car.

Car owners also tend to change the oil as soon as it turns black. This habit causes unnecessary waste if the lubricating oil has not reached the cycle of use date or mileage.

The combustion process of fuel produces carbon soot, forming dirt that sticks to the surface of the engine's internal parts. With the cleaning properties of lubricating oil, the dirt is dispersed into small particles and retained in the lubricating oil. Therefore, the lubricating oil will quickly turn black after a short period of use. This proves that the lubricating oil has performed its cleaning function well.

"We do not necessarily have to change the oil immediately when it turns black if it has not reached the cycle or date of use," said Mr. Duy Duc.

Another habit is to only replace the lubricating oil without replacing the lubricating oil filter. The lubricating oil filter should be replaced after 2 oil changes to ensure good flow and quality of lubricating oil circulating inside the engine.