What level is SL engine oil?

[LeJuliana]

SL engine oil is one of the API quality grades, specifically designed for gasoline vehicles. Among the commonly used quality grades of engine oil, it is considered a lower-level grade. Currently, SL engine oil is mostly mineral oil. In the classification of engine oils, one parameter is the API quality grade. Gasoline engine oils are graded from SA to SP, and this designation is essentially used to describe the quality of the oil. The engine oil quality grade, also known as the performance grade, is an important basis for correctly selecting lubricants. The selection of diesel engine oil quality grades is based on two factors: the sum of the mechanical and thermal loads of the automobile engine, expressed by the strengthening coefficient, and the severity of the engine operating conditions.