How many grades of engine oil does the complete Castrol series have?

[McAdalynn]

Castrol's Edge and Magnetec series of engine oils are both rated at SN grade. The Castrol GTX series has two grades, SN and SM, while the Castrol GTX Silver is rated at SL grade. The engine oil grade is SJ, with the grades descending from highest to lowest. Here is some relevant information: 1. API is the most common international certification standard for engine oils, standing for the American Petroleum Institute. Engine oils that pass API testing and certification can display the API double-circle logo on the bottle. The grading standard for engine oils is primarily based on the oil's fluidity at high temperatures, high-temperature cleanliness, diffusion filtration, oxidation stability, wear resistance, corrosion and rust prevention, catalyst compatibility, and environmental requirements (this part will be mentioned later). Currently, there are 12 grades in total: SA, SB, SC, SD, SE, SF, SG, SH, SJ, SL, SM, and SN, with SN being the latest. 2. The 'S' represents gasoline engines, and the following letters indicate the grade. The common marking on the can is SJ/CF, where the 'C' after the slash refers to diesel engines, and the grading method is the same, meaning the further the letter is in the alphabet, the higher the grade.