What does the specification model of engine oil mean?
3 Answers
The specification model of engine oil is explained as follows: Composition of engine oil designation: The engine oil designation consists of two parts: classification and viscosity specification. Classification of engine oil: The classification of engine oil is represented by a combination of two letters. The "S" series represents oil for gasoline engines, with general specifications ranging from SA to SN (in alphabetical order, but without SI). Each subsequent letter indicates better performance than the previous one, with more additives to protect the engine. The later the letter, the higher the quality grade. International brands usually have engine oil grades above SF. The "C" series represents oil for diesel engines. If both "S" and "C" letters are present, it indicates that the oil is suitable for both gasoline and diesel engines. Viscosity specification: The designation following the classification indicates the viscosity specification, such as "15W-40, 5W-40". The "W" stands for Winter, and the smaller the number before it, the better the low-temperature fluidity of the oil, indicating a lower usable environmental temperature and better protection for the engine during cold starts. For example, 5W represents resistance to external low temperatures of -30°C, while 20W represents resistance to -15°C. The number after "W" indicates the oil's high-temperature resistance, with higher values indicating better protection at high temperatures.
When it comes to oil specifications and models, based on my driving experience, it's all about those codes on the oil bottles, like 5W-30, which help us choose the right oil for our cars. First, let's talk about the SAE rating. For example, the 'W' in 5W stands for winter, and the '5' indicates better fluidity in cold weather—the lower the number, the smoother the engine starts in winter. The '30' after it refers to the viscosity at high temperatures; a higher number means better engine protection in summer but might increase fuel consumption. The API symbol, like SP, represents the latest quality standards, preventing engine wear and reducing emissions. If you don't understand this, using the wrong oil can lead to increased engine noise or reduced lifespan. It's crucial to check the manual for the right oil—experienced drivers like us often choose oil based on the climate. And with synthetic oils, clear specifications mean you won't waste money on unnecessary repairs.
When choosing engine oil, I check the specifications on the bottle to avoid wasting money and damaging the car. In the SAE number 5W-30, the smaller number before W means better cold starts in winter, while the larger number after W ensures stability in summer. For API ratings like SN or SP, the newer the number, the better the protection, reducing wear and carbon buildup. I think many people overlook this—oil changes should follow the manual, or you'll face slow starts in cold weather and higher fuel consumption. Regular oil changes are also crucial; using the right specs can extend engine life by tens of thousands of kilometers, saving money and peace of mind. Climate matters too—I use a lower W in the north, while in the south, the latter number can be smaller. Just remember the numbers correspond to temperature and standards.
