Saw this and thought of you lot.
Dave
Well, I'm still experimenting. In the 70's and 80's, I used Castrol 20w-50. Back on the road in 2013, I used Castrol 20w-50 High Mileage because it was a part synthetic. Since my total rebuild and 750 kit, I ran Castrol 20w-50, mineral for a 400 mile break-in and same again for a 600 mile break-in.
I then put in "Castrol Edge Supercar 10w-60 Advanced Full Synthetic", and after ~2200 miles, it wasn't black with silver swirls. It was actually kinda reddish with only faint silver swirls. But at $14 a liter, that's a little too much.
Next I tried Mobil 1, 20w-50 for V-twins. Also fairly clean at ~2300 miles. Used the Mobil 1 again and still fairly clean. It's almost $10/qt now.
Presently, I'm using Liquimoly 10w-60. I'm about to change it for the rally. I found it for $43 for 5 liters on Amazon. About $8.50/liter. I can handle that. I get 2 oil changes and a little extra. I'll see how clean it is in a couple of days.
By the way, I also add a 1/3 of a bottle of Rislo Zddp at each change. Always add zinc!
Next, I will try the Mobil 1, 15w-50. It already has zinc in it. It's about $24 for 5 quarts. The best deal , so far, for full synthetic.
What's the best oil? I dunno!
So is that one vote for peanut oil?I like peanut butter sandwiches.
What did PopEye do when he burned his fingerHowzabout Olive Oyl?