Actually, I've read a few places, I think the TDI forum place is one, that
syntec isn't actually a synthetic only a high quality regular oil.  I used
to use Syntec but now switched to mobil 1 15W50 cause I did not like the
idea of paying synthetic price for an oil that isn't synthetic.  I believe
they were sued for false claims also.  There is a site that breaks down
different oils and explains what all the stuff means.
http://vger.rutgers.edu/~ravi/bike/pages/pages/docs/oil.html     Take a
look.   Just my experience.

Tim Vogelin   84'  Wolfsburg

Using Castrol 15W50 Syntec (no 20W50 in stores around here !) in my '87
Westy.  I switched to this oil about a year ago and find it great so far.  I
think it's more a peace of mind thing as I can't see what's happening inside
the engine and won't know anything pro or con until   rebuild time comes
around. I choose Castrol Syntec for a few reasons.  List members recomended
it, it's usually "on sale" at Canandian Tire where I shop for bargains, it
mixes well with regular oils and Castrol has a good image to me.