Should the CS75 use 5W30 or 5W40 engine oil?
3 Answers
It is recommended to use the original 5W30 grade engine oil. 5W30 has better fluidity compared to 5W40, which can reduce fuel consumption and heat up the engine faster. The difference between 5W30 and 5W40 engine oils lies in their viscosity. The higher the viscosity, the more oil the engine consumes, the higher the noise level, but the better the sealing performance. Therefore, when selecting the viscosity of engine oil, the age of the vehicle should also be considered. New cars have smaller gaps between engine components, so lower viscosity oil should be chosen, while vehicles with severe engine wear should opt for higher viscosity oil. The 'W' stands for winter. The smaller the number before the W, the better the oil's low-temperature fluidity, the lower the usable environmental temperature, and the better the engine protection during cold starts. The number after the W indicates the oil's high-temperature resistance. The larger the number, the better the oil's protective performance at high temperatures. For example, 5W40 means it can be used normally at temperatures below 40 degrees, while 5W30 means it can be used normally at temperatures as low as -30 degrees. In principle, as long as the oil does not deteriorate and is of sufficiently good quality, the oil film will remain intact, fully utilizing the oil's performance to protect the car. However, if the oil contains a significant amount of water, its lubrication performance and viscosity will degrade, the friction-reducing effect of the oil film will weaken, and the oil's inevitable deterioration may lead to more severe accidents, such as engine seizure or bearing failure.
Regarding whether to use 5W30 or 5W40 oil for the CS75, I personally think it depends on daily driving conditions. In northern winters when it's as cold as a refrigerator, 5W30 has better low-temperature fluidity, ensuring smooth cold starts without harming the engine. However, if you live in high-temperature southern areas or frequently drive long distances on mountain roads in summer, 5W40's higher high-temperature viscosity can better protect the engine, preventing oil thinning and component wear under high heat. Additionally, most CS75 1.5T engines recommend 5W30, as stated in the factory manual. I've personally tried switching to 5W40 and felt slightly heavier acceleration but reduced engine noise. For daily commuting, 5W30 is more fuel-efficient, saving some money on gas. In short, choose the most suitable option based on your local temperature and driving habits.
As a seasoned veteran in long-term vehicle maintenance, I've seen quite a few CS75 cases. 5W30 is usually the preferred choice—its moderate oil viscosity matches modern engine designs and is particularly friendly to the 1.5T models, improving fuel efficiency while being environmentally friendly. However, if the engine is older or the owner frequently carries heavy loads or drives aggressively, 5W40 offers better resistance to high-temperature wear and reduces failure rates. I recommend checking the CS75 owner's manual, which contains specific specifications. Regular oil changes are also crucial—don't just focus on viscosity; also consider the API certification standard to ensure consistent performance. When changing the oil, visit a professional shop for inspection to avoid mistakes that could affect the car's lifespan.
