In article .com>,
says...

>As someone else noted the turbo runs in engine oil, so just be perform
>regular oil changes and use synthetic. I've always changed oil every
>3,000 to 3,500 miles no matter the car, and I've used synthetic in my
>cars since 1996. I see the difference at 200,000 miles when the engine
>still runs smoothly, gets good milage and when you look down into the
>oil gallery there is no evidence of sludging. Frequent oil changes are
>a cheap alternative to a prematurely wornout engine.

Synthetic is not needed to get long life out of a turbo. I had a Dodge Omni
GLH turbo. I sold the car with 153k miles on it without touching the turbo.
I used whatever brand name oil was on sale and changed it every 3k miles.
I also let the car idle for a minute or so before I shut it down. That the
core was water cooled also helped.
----------------
Alex