My '85 Westy had something over 170,000 at the time I first tried
synthetic oil.  Not long after that the crankshaft seal (flywheel end)
failed and I was dousing tailgaters (and my own tailgate) with engine
oil.  Coincidence?  Maybe.

Anyway, I dropped the transmission and replaced that seal, pilot
bearing, and clutch assembly along with a bunch of other little things
while I was there.

I've been using synthetic oil ever since without any issues and I'm
glad. In Northern Maine, my van really likes the 5W 50 oil for winter
use.  Oh ... and it now has more than 198,000 miles on it.

Mike

Wesley Pegden wrote:
> My '84 1.9l is pushing 198,000 miles.  Although I've thought of
> switching it to a synthetic (like Mobil 1 15w-50),  my understanding is
> that this may be a bad idea on my long-running engine due to the
> condition of seals etc.  Am I right?  Should I keep doing what I'm
> doing? (It aint broke...) or should I make the switch?
> -Wes
> '84 manual 1.9l
>