[s-cars] super tech brand synthetic oil - thoughts?

[Dave Ellis]

Lee Levitt wrote:
> Tim writes:
> 
> 
>>I haven't put it in my S4 as it already had 140,000 mi when I 
>>bought it.
>>Most of its oilchanges were at the dealer so I doubt it was 
>>seeing synthetic.  I was concerned about converting to 
>>synthetic on high mileage engines.
> 
> 
> Tim,
> 
> I've heard lots of *old* stories about that. At 180K miles I converted a
> 2.5L Mercedes turbodiesel to synthetic, and have not had a problem.
> 
> Do you know of *anyone* that has converted an engine in the past five years
> to synthetic and had a problem?
> 
> Lee


Converting a high mileage engine to synthetic does not cause problems 
per se, that's a bit of an urban myth.  What can happen though, is that 
if your high mileage engine has gaskets that have worn out and are no 
longer sealing properly, switching to synthetic with it's typically 
higher detergent action can actually cause the crud/gum/varnish that had 
plugged small holes in old gaskets to be cleaned out, and the owner is 
suddenly aware of "new" oil leaks they had never noticed before, even 
though the leak had probably appeared in the past but quickly gummed up 
and stopped before being noticed.

I've switched several high mileage German cars to synthetic, and have 
never had a problem until the S4.

When I switched my '93 S4 to synthetic a few months after purchasing it, 
I had three oil leaks develop in the space of a couple of weeks. 
Looking at the leaks though, all of them showed lots of old baked on 
"dribble" marks where oil had previously oozed out of those spots at 
some earlier time and then stopped.  Replacing the gaskets, it was clear 
they were well worn and should have been replaced *much* earlier.

So if your engine is in good shape, then you have no worries switching. 
  If you already have some pre-existing problems masked by crud though, 
the synthetic may highlight these areas for you as the crud is cleaned out.

-Dave