To bring back hope to those pondering a switch to synth oil - I did it a few months back (September '03 or so) on the 1988 90 Q and no leaks have sprung. No engine flushing and even mixed synth and dyno for awhile, no trouble so far. Odo shows 264, 000 km, it was under 260,000 at the time of switch. Merry motoring TT