As the saying goes, buying a car is easy, but maintaining it is difficult. For car maintenance, it has always been a concern for everyone. Especially the selection and replacement of oil filters, how to replace them, and how long to replace them. In the past, we have also talked a lot about this topic, such as whether fully synthetic engine oil can be changed every 10000 kilometers, and whether the viscosity of the oil is better at "30" or "40". What is the difference? Also, can maintenance be done outside of the 4S dealership? Today, based on my personal experience of vehicle maintenance, I will answer these questions one by one.

For the question of choosing fully synthetic or semi synthetic engine oil, it can be roughly said that turbocharged models use fully synthetic engine oil, while naturally aspirated models can use semi synthetic engine oil. Of course, this is not absolute. Which car model should I choose? I still need to consult the 4S store to confirm. My car chose fully synthetic engine oil from the beginning because it has a turbocharged engine. For various reasons, I chose not to do it at the 4S dealership since the second maintenance. I personally have a thorough understanding of where to do maintenance. Firstly, the new regulations clearly state that consumers have the right to choose their consumption. If we are doing maintenance outside, it is best to choose a qualified and legitimate store, and after each maintenance, request proof of maintenance records. For the question of choosing fully synthetic or semi synthetic engine oil, it can be roughly said that turbocharged models use fully synthetic engine oil, while naturally aspirated models can use semi synthetic engine oil. Of course, this is not absolute. Which car model should I choose? I still need to consult the 4S store to confirm. My car chose fully synthetic engine oil from the beginning because it has a turbocharged engine. For various reasons, I chose not to do it at the 4S dealership since the second maintenance. I personally have a thorough understanding of where to do maintenance. Firstly, the new regulations clearly state that consumers have the right to choose their consumption. If we are doing maintenance outside, it is best to choose a qualified and legitimate store, and after each maintenance, request proof of maintenance records.

Okay, let's talk about returning the oil. It's been almost 10 months since the last maintenance, and the mileage is 7051 kilometers. Many people are asking, can fully synthetic engine oil be maintained every 10000 kilometers? I think it depends on the specific situation, such as the driving environment and frequency of use. Firstly, the driving environment. If 70% or 80% of the road conditions are congested or driving at low speeds in the city, then I think 10000 kilometers can be considered the limit. My usual driving situation is 60% smooth road conditions and 40% congested road conditions. Although the situation seems good, after 7000 kilometers, I still feel a noticeable decline in engine oil, which is reflected in acceleration performance and engine noise. In addition, another important point is that the "lifespan" of engine oil is closely related to time.

Fully synthetic engine oil claims to be able to be used for more than 1 year, but the amount of 1 year here is still based on ideal conditions. Because after leaving the enclosed space, the engine oil will gradually decay with the influence of the environment. Although my car uses fully synthetic engine oil and the mileage is not too long, 10 months is indeed not short, so I have decided to change the engine oil at this time. It should be noted that based on personal experience, even if it is not replaced now, there is no problem, and driving for another one or two months or 2000 or 3000 kilometers is still within the normal range. Just in terms of experience, there will be some impact, and personally, I am more concerned about the driving experience. So, my advice to everyone is that if the driving environment is not too bad (often stuck in traffic and driving at low speeds), I think fully synthetic engine oil can be used for 10000 kilometers, but the premise is that you choose genuine and high-quality fully synthetic engine oil.

There is one thing I need to specifically explain. As we all know, changing the oil must be done simultaneously with changing the oil filter. In the eyes of many people, engine oil is important, but they often overlook the filter. In fact, both engine oil and oil filter are equally important. When we choose fully synthetic engine oil and prepare for a 'long-lasting battle', we must choose a long-lasting filter to match it in order to achieve good results. Many ordinary filters can only support a driving range of 5000 to 6000 kilometers. At this point, although your oil condition is still completely OK, the filter has lost most of its filtering effect, which can still have a negative impact on the engine.

Finally, regarding the selection of oil viscosity, I believe there is not much difference. Generally speaking, Japanese cars use low viscosity engine oil, while European cars, especially turbocharged models, generally use high viscosity engine oil. My car belongs to the European series. According to the advice of the 4S dealership, you can use oil with a viscosity of "30", and of course, there is no problem with the "40" grade. The difference between the two lies in fuel consumption and power experience. For this maintenance, I specifically changed the oil to a viscosity of "40". After experiencing it personally, I can still clearly perceive subtle differences. On the one hand, it is mainly reflected in the perception of power. As the engine number increases, the viscosity of the oil becomes higher. Simply put, at the same speed, the engine will run more "hard", and at this time, the fuel consumption performance will also be different, that is, the fuel consumption will increase.

According to previous data from the driving computer, the average fuel consumption for normal driving in the city is around 8.5 liters. After changing to oil with a viscosity of "40", the average fuel consumption increased to over 9 liters. The decrease in power and the increase in fuel consumption are changes on one hand, but on the other hand, when the engine revs up (above 4000, 5000 rpm), the engine noise becomes significantly lower. We can also understand this as high viscosity engine oil can reduce engine noise and better protect the engine, especially for friends who enjoy intense driving. It is highly recommended to replace with high viscosity engine oil. But for ordinary family cars, oil with a viscosity of "30" is very suitable, and its biggest advantage lies in fuel consumption.