According to the manufacturer's instructions, the Mercedes-Benz C200 requires 5W30 oil, and approximately 5 liters of oil are needed during maintenance. Mercedes-Benz has high requirements for oil quality and flexibly uses oils from Shell, Mobil, and Castrol brands. Naturally aspirated engines have standard requirements for oil quality and can use mineral oil or semi-synthetic oil. If the consumer's financial situation allows, full synthetic oil can be used for maintenance. When replacing the oil, it is necessary to simultaneously replace the oil filter. The oil filter is used to remove impurities, metal particles, sludge, and other contaminants from the oil. Only filtered oil can remain clean, thereby extending the lifespan of both the oil and the engine. If the oil filter is not replaced when changing the oil, the new oil will be contaminated by the residues left in the filter's paper element, causing the new oil to turn black quickly. Additionally, if the oil filter is not replaced for a long time, its filtering efficiency will significantly decrease, mostly failing to achieve the desired filtering effect. Prolonged driving under such conditions will rapidly wear out the engine's internal components, and in severe cases, it may lead to oil burning. It is recommended to replace the filter whenever the oil is changed. The viscosity of oil changes with temperature, so special attention is needed to its performance under both low and high temperatures. For example, in 5W-30, the first number indicates low-temperature fluidity, with 5W representing the ability to withstand temperatures as low as -30°C. The smaller this number, the better the low-temperature fluidity, ensuring smoother cold starts for the car. The latter number represents the oil's kinematic viscosity at 100°C, with higher values indicating better maintenance of viscosity under high temperatures, which can also be understood as better lubrication performance under high-temperature conditions. When selecting oil, the following considerations should be kept in mind: Choose oil based on the engine's requirements. It is unnecessary to use overly advanced oil for engines with lower requirements, nor should lower-grade oil be used in engines with higher demands. Multi-grade oil should be preferred whenever possible. Multi-grade oil offers benefits such as cost savings, longer lifespan, and high efficiency, providing better protection for the engine. Due to the characteristics of multi-grade oil, it may appear darker prematurely and exhibit lower oil pressure compared to conventional oil, both of which are normal phenomena.
