How to Identify Oil Quality by Its Model Number?

[DiOmar]

In terms of price, the quality of engine oil can be judged to some extent, as you get what you pay for. High-quality oil generally comes at a higher price. The oil model number consists of two parts: the grade and viscosity specification. Generally, SN and SM grades are considered good. Synthetic oil is better than mineral oil because it is cleaner, purer, and provides longer engine protection compared to mineral oil. Good-quality oil does not have a strong, unpleasant odor; instead, it has a mild, pleasant fragrance. In contrast, inferior oils often have a pungent smell. Generally, synthetic oil should be replaced once a year, while mineral oil requires replacement every six months.

[Sousa]

When I first started driving, I was also curious about how to tell the quality of engine oil by its specifications, and later I learned that those numbers and letters aren’t randomly assigned. For example, the common SAE 5W-30—the '5W' indicates easier cold starts in winter, and a smaller number is better; the '30' represents stable lubrication at high temperatures, with a higher number offering better engine protection. API ratings like 'SP' are industry standards, where a higher grade means better anti-wear and cleaning performance, far superior to older standards like 'SN.' Full synthetic oil is usually labeled as such, with terms like '全合成' or 'Full Synthetic,' offering longer lifespan, better cleaning effects, improved fuel efficiency, and fewer repairs. My advice is: don’t skimp on oil—choosing the right specification means fewer car troubles. Always check the owner’s manual for the correct match, pick a lower 'W' value for cold winters, and a higher second number for hot summers. The right oil can extend your engine’s life by tens of thousands of kilometers.

[SamanthaMarie]

In the past, I often drove long distances, and the oil grade is directly related to engine performance. Look at the two numbers in the SAE section: the first one, like 0W or 5W, indicates how quickly the engine starts in cold conditions—a lower W value means better fuel efficiency and easier starting. The latter number, such as 20 or 30, represents high-temperature protection—a higher value is better for high-speed driving to avoid overheating. The API rating, like SN or SP, indicates oil quality, with newer letters representing higher standards—SP stands for the latest anti-knock and energy-saving specifications. The difference between mineral and synthetic oil can also be seen in the grade description, with full synthetic oils often labeled as 'synthetic,' offering longer-lasting engine protection. I recommend always checking the certification labels on oil bottles, such as ILSAC GF-6 for better fuel efficiency, and avoiding older oils with lower API ratings, as they can cause carbon buildup and wear. Choosing the right grade makes the engine run quieter, and even mechanics agree it's reliable.

[McSilas]

As an office worker, I'm concerned about high fuel consumption during my daily commute. The SAE rating in motor oil specifications is key: for example, a lower W value in 5W-20 means better winter fuel efficiency and quicker starts, while the smaller number 20 indicates lower viscosity and reduced resistance for better energy efficiency. For API ratings, SP is currently the best, offering optimal protection for modern engines against overheating or wear. Oils labeled 'Synthetic' are superior to mineral oils, being more durable and environmentally friendly. My vehicle's manual recommends specific oil grades – using mismatched oil can cause engine overheating and problems. When selecting oil, prioritize higher API ratings and lower viscosity grades to save money while being eco-friendly.