What does the API on the oil drum mean?

API grade represents the grade of oil quality. API oils are divided into two categories: the series starting with S represents gasoline engine oil, and the series starting with C represents diesel engine oil. The grades of engine oil are classified as SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM and SN, and the grades increase with the lower letters, and the SN grade is the highest grade of engine oil.

The summer brands of AE lubricating oil viscosity classification are 20, 30, 40 and 50 respectively. The larger the number, the greater the viscosity and the higher the applicable maximum temperature.

Extended data:

Precautions:

When adding engine oil, it should be noted that the amount of oil is slightly lower than the scale on the dipstick: engine oil is extremely important for the movement of the engine because it shoulders two major functions of lubrication and heat dissipation. Therefore, you can't be short of oil at any time. But the consequences of excessive addition are very bad.

The amount of oil should be slightly lower than the scale on the dipstick, and don't overfill it. Excessive engine oil will not only increase the rotation resistance of the crankshaft, but also reduce the output power of the engine. Even those excessive engine oil will flee into the combustion chamber to participate in combustion, thus causing engine oil combustion and blue smoke, and even increasing fuel consumption.