[Biturbos4] Mervel Mystery Oil

Keman keman at interwolf.net
Fri Dec 10 14:05:08 EST 2004

Let me be the first to say not to even put it into the trunk in the bag
from the store which you purchased it from.

I've certainly worked on cars enough over the years to be familiar with
crazy attempts to get more detergents into oil, ie: using ATF instead of
oil to break down all the varnish etc (Done that!) ... but at this point
what I've seen from the dudes at Mobil or Redline or Amsoil, there is no
need and at best it might cause problems.

Just my .02 ... if you want to spend more money on oil, use redline.

As far as the viscosity... since I know this topic will come up again,

5W-30 in the winter, 10W-30 in the summer .. pure synthetic.

15W-50 under very hard use / high heat conditions in any season.

I know Audi recommends 0W-30, I know some people put in 0W-40 and swear by
it. Myself, I've determined that is only for mileage. Not longevity.

Over the last 6 years the engine bearing tolorances have not changed one
bit, yet a late 90's 1.8T owners manual says in big bolt print "Use 5W-30
if all other grades are not available and do not drive the engine at high
speeds on this oil" ... they recommend 15W-50 for all temps down to 0
degrees F. Flip forward a couple of years and poof.. wow.. what's this.
0W-30. No warning about using 5W-30 at all.

I've had the turbos apart, they don't care what oil you put into them so
long as the pressure isn't too high. There aren't any mysteriously
microscopic oil passageways that 10W-30 would starve. Pretty much anything
you feed them turns into white froth that spills down back into the oil
pan that resembles coffee with a bit too much cream. KKK turbos don't even
want a lot of pressure, if you push too much you just push it past the oil
seals. How turbos seal the oil is a fascinating piece of science .. the
first step is actually centrepetal force. The oil is 'flung' off the axle
into a cavity that has baffles, and from there gravity drains it away. Air
must be present in these baffles, so if a turbo drain line is ever raised
above the turbo they'll fill up and the turbo will gush oil out into the

Don't get me wrong, the 2.7T's oiling system is incredibly complicated,
with check valves to hold oil, pressure valves to keep oil going to the
main bearings if pressure falls below a certain point .. more pressure
valves to direct oil to the undersides of the pistons when oil pressure
goes above a certain point, it's truely a masterpiece to behold. Whatever
grade you run, I would say the most important thing is that you run
/synthetic/ and change it out at 5k miles tops.

I did this since the first 1000 miles, and 105F degree track abuse and
TONS of street abuse in california bay area heat.. (I floor it away from
every light, I speed like a maniac) at 80k miles the turbo wheels had
perfect shaft side play and at 96k miles it still didn't burn a drop of
oil between changes. With my luck of ditching my S4 because I needed a
warranty... that car will probably run forever.

At least I'm back into the turbo world. Tomorrow I pick up a 1988 Ford
Thunderbird Turbo Coupe 5 speed manual. 78k miles on the clock, it's my
new beater toy. Unfortunately I can't find any S4's or even 1.8T's for
$1200 but if anyone wants to sell me theirs for that price, be sure to let
me know. :)

- Keman

> Hi all.  I have been lurking here for three years.  In that time I do not
> recall any discussion of the wisdom of putting Marvel Mystery oil in with
> the new oil on an oil change or even treating the fuel with the stuff.  I
> read several aviation related mail lists and its use seems pretty common
> on aircraft engines....    Any  chance MMO would cut down on the turbo
> oiling problems on our cars?
> Thanks,
> Paul Magid
> pmagid at magid.org

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