I have been running 20w50w Castrol oil for years no problems, changed to 10w-50w Castrol oil for my 2013 DL650.Mmmm... I just put 20w50 Valvoline Jaso MA conventional in the bike and took her for a nice ride. I love this oil in this bike. All butt dyno analysis, but it's the nicest oil I've run in this low rpm torque beast. Improved shifting, engine noise, low rpm confidence (don't ask me to explain that one.. the bike just feels better at low rpms on this oil). Now if you were a 5k-8k rpm rider, you might want something thinner 😏
I rarely find myself over 4k rpms unless it's deliberate. If I'm just riding, this bike loves 3-4k rpms all day in almost any scenario.
Old school dinosaurs for the win and let The Big Oil Thread flaming begin! 😁