The "Bob is the oil guy" website is great if you are talking about crankcase oils.

Renewable lube "synthetic". Better check the definition of "synthetic" motor oil. I haven't seen anything new on Renewablelube's site that would make it particularly suitable for a model engine. Though the SAE 40-50 engine oils would be fine.

Model airplanes using biodegradable lubricants? Who would have thunk it? Wait a minute what is castor oil?

After run oil issues:
http://www.rcuniverse.com/forum/fb.asp?m=4586886

The Plantomot stuff looks interesting. Manufactured by Fuchs of Germany, it doesn't seem to be available in the US. Biomot produced by Panolin of Switzerland is just being introduced in the US. But at a 25 liter container unless I decide to put this in my car, I won't be trying it quite yet.

Ugo, a while back Steve (ama1836) posted his success with a 2% oil mix in JP8. Using your theory on dilution why has his engine survived? Amsoil's Saber has a viscosity, at 100C, of 13.5 cSt for your reference.