Early on I was using mobil1 synthetic, recently I've been running the cheapest wal-mart oil I could find. Just keep oil in the engine, and change it when it's dirty.
Anymore I've been running 10w30, I don't run my stuff in colder weather anymore.
BTW, the turbo is water cooled, which prevents a lot of the issues early turbo engines saw (many did not have water-cooled turbos)