Engine oil grade and label analysis

In car maintenance in daily life, engine oil is something everyone is familiar with, but at the same time, it is very strange and only knows that you need to change the oil. What kind of oil is more suitable for our car, and which one is suitable?

Oil grade  
1. The engine oil used in gasoline engines starts with "S", and common ones are SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, SN. The performance gradually increases from A to L. With each letter, the performance of the oil will be better than the previous one, and there will be more additives to protect the engine in the oil; the later the letter, the higher the quality level, the higher the oil in international brands. Most levels are above the SF level. Most of the commonly used motor oils in the market are SN, SM and SL.
    

2. The engine oils used in diesel engines start with "C", and common ones include CA, CB, CC, CD, CE, CF, CF-2, CF-4, CG-4, CH-4, and CI-4. We usually use gasoline engine oil.
    

3. The series starting with "C" represents diesel engine oil. If the two letters "S" and "C" are present at the same time, it means that the engine oil is a general-purpose type.

Motor oil label

What do we usually mean by 5W-30, 15W-40, etc.? W is the first letter of "winter" in winter, and the number before W represents the temperature resistance. 0W, 5W, 10W, 15W, and 20W represent -35 ° C, -30 ° C, -15 ° C, -10 ° C, and -5 ° C once.   The smaller the number in front of it, the better the low-temperature fluidity of the oil, which means that the available ambient temperature is lower, and the better the engine's protection ability during cold starts, the number after W represents the movement of the oil at 100 ° C Viscosity, the higher the value, the higher the viscosity. 40 means that the standard of kinematic viscosity at 100 degrees Celsius is between 12.5mm2 / s and 16.3mm2 / s, which is definitely not something that some people say can be used below 40 ℃.

Oil classification