Date: 29 Sep 1998 16:17:09 GMT From: saab85900nopsamcom (Saab85900) Subject: Re: Are oil additives bad for your Saab?
>Chieko Mori wrote: >One interesting warning here is about switching from >mineral to synthetic oil, and vice-versa. Basically, it >says, when going from mineral to synthetic, flush first, >and be aware that your gaskets and seals could leak >as a result of the changeover. As for going from >synthetic to mineral, it says...don't. >Anyone care to corroborate this? Most of it is mis-information. I always recommend a flush before changing to synthetic in any engine with more than 15,000 miles on it. This will clean out any sludge or varnish left by the non-synthetic. However, it isn't mandatory. The synthetic will clean out the stuff over a couple thousand miles, but you may have to change the filter after a couple thousand, or drain the oil prematurely if you don't flush. In older engines where the oil was not change regularly, it is possible to have glop covering up worn seals or gaskets. Changing to synthetic (or even a different brand of non-synthetic) can clean up the glop, and you'll find pre-existing problems. Far as I know, no synthetic on the market will attack seals or gaskets. You can always go back to non-synthetic, though I can't imagine why anyone would want to do so<g> Dick in Falls Church, VA Using and selling AMSOIL (First in Synthetics) over 21 years