What do the different oil ratings mean? The oil I put in my bike a few weeks ago says API SJ. what does this mean? I didn't realize this until after i had changed my oil. The tag on the bike says something different, don't remember right now. Is this gonna harm my engine in any way? I use yamalube because I have always been told that its the best, when a suzuki dealer says use yamalube it must be good right? Any info would be great.