Found on the web that the GX uses SJ5W-30. Is this synthetic or dino? What does the SJ mean?

 

"S" means oil used for gasoline engines. "J" is the quality level of the oil. So, SJ oil can be used in an engine that calls for SA, SB, SC, etc. The codes are part of the API, American Petroleum Institute. Just looked the stuff up on the internet