Just my 2cts. I run Mobil 1 15/50 full syn. in my 2001 gen. 1. Change said oil every 4 thousand miles, with filter change every other oil change. Bike seems to be fine, with 60K miles on it.
Now the ol' 2002 gen.1 wreck, with 131K miles on it, has only seen 20/50 oil on sale at the local auto parts store from new! Lol! Name brand oil, that I change every 2 thousand miles. The device continues to function perfectly. Riding around town, or short rides it hardly uses any oil. If I hammer it, like I did two weeks ago, on a 900 mile sport tour ride up north, then it will use oil. Funny thing is, guys behind me, never see any smoke from the bike? Anyway, this device runs fine.
You all have a great day, now.
Dean