Just in time for the summer debate season, this month's Consumer Reports
has an interesting report on a test of different oils they did.
This is all from memory, but here are the essentials I remember:
Tests were done in NYC cabs, for 60K miles. Oil change every 6000 miles.
Then a tear down and measure piston, valve, and bearing wear, sludge
buildup, varnishing.
Basically they found no significant difference in engine wear in those
engines using a "rated" oil. (Current rating is "SH" for gasoline engines.)
They also found no difference in wear between 5W-30 and 10W-30 oils.
They felt that the test wasn't sufficient to measure sludge buildup, as
this requires the engines to sit cold and cabs never sit for long.
There was no significant correlation between brands and varnishing.
Their take on synthetic oil was it behaved better under extreme hot/cold
conditions and was recommended as such with normal frequency oil changes.
There was also an interesting summary of different brands  of oil and
whether they had different formulations in different states.
Their conclusion:
buy the brand that's cheapest in the viscosity change recommended by your
manufacturer;
change oil every 7500 miles or at manufacturers suggested interval to
preserve warranty;
use synthetic oils in extreme conditions: hot, cold, towing, etc;

just thought you'd want to know...
-rick

PS: an 87 Synchro (NOT a camper) showed up in the local newspaper today.
80K miles, US$9000 I think it was. I don't remember if it was a local phone
number, but assume its somewhere west of Seattle to be safe. Let me know if
you're interested and I'll dig up the phone number.

Rick Gordon
Bainbridge Island, WA, USA
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rickgo@halcyon.com
http://www.halcyon.com/rickgo/
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