Oil is like beer, you have the taste and you have the alcohol content. I tend to pick a major brand, change it often enough, stick with it, and select the 10W40 general oil weight spec'd by Honda, Suzuki, etc of that era. I like to go by decades on the planet, a 45+ year old bike (s) with tens of thousands of klicks, and a slew of empty oil cans to form my opinion. Lots of stuff is invented concerning our secret sauce, kind of like tainted versions of history lol. Taken to extremes an incorrect beer choice can cause the runs, but also very important is to remember that oil is like beer in another very important way, you only rent it for a short period of time.