How to Choose Engine Oil for Cars?
2 Answers
Methods for selecting engine oil are as follows: 1. Choose the low-temperature viscosity of engine oil: The low-temperature grade of engine oil mainly determines the cold-start performance, low-temperature anti-wear capability, and low-temperature fluidity of the oil. When selecting the low-temperature grade, it's essential to consider not only the low-temperature viscosity of the oil but also its pour point. Different brands of the same grade of oil may have different pour points. 2. Choose the high-temperature viscosity of engine oil: The high-temperature viscosity grade is calibrated based on the oil's 100°C dynamic viscosity value. It indicates the oil's viscosity under the engine's warm operating conditions. The higher the high-temperature viscosity grade, the greater the oil's viscosity when the engine is warm. A lower 100°C dynamic viscosity can reduce fuel consumption and engine noise, while a higher 100°C dynamic viscosity provides better protection for the engine during ultra-high-speed operation. It's important to note that even oils of the same model may have different high-temperature viscosities. When selecting the high-temperature viscosity, consider the vehicle's actual usage conditions. If fuel efficiency and quiet operation are priorities, choose a lower viscosity. If frequent rapid acceleration or high RPMs are common, opt for a higher viscosity. For Volkswagen vehicles, it's necessary to select an oil with a high-temperature high-shear viscosity of 3.5cP or above, and within the same model, choose a relatively higher viscosity. 3. Select and determine the quality grade of the engine oil, i.e., the API grade. The principle for choosing the oil's quality grade is to always follow the level specified in the vehicle's manual, opting for a higher rather than a lower grade. 4. Choose and decide between mineral oil and synthetic oil. The difference between mineral oil, semi-synthetic oil, and full synthetic oil does not lie in their lubricating performance but rather in their viscosity-temperature characteristics, stability, durability, and cleanliness for the engine. Higher-grade oils perform better in these aspects.
As a family car owner who drives frequently, choosing engine oil requires practicality and cost-effectiveness. First, I check the vehicle manual for the recommended type and viscosity, such as common grades like 5W-30 or 10W-40. These numbers indicate the oil's fluidity—lower numbers like 5W mean quicker starts in cold winter weather, while higher numbers like 40 offer better protection in hot summer conditions. Then, I consider the budget: mineral oil is cheaper, but I often opt for semi-synthetic oil because it lasts longer, stretching 5,000–6,000 kilometers per change, saving money and hassle. I also pay attention to brands—trusted names like Shell or Mobil are reliable and harder to counterfeit. Driving habits matter too; since I mostly commute in the city with frequent traffic jams, I don’t need high-performance oil. At the auto repair shop, I discuss local climate effects with the mechanic—for example, in humid southern regions, I choose oil with good moisture resistance. In short, sticking to the manual and avoiding overcomplication works best.
