Re: Synthetic oil in an older vehicle

[Henri Baccouche <henrib@xxxxxxxxx>]

120k with Chevron/Shell/Exxon conventional 20W-50 on my 86 325......with
2.5-4k oil changes.
When I sent the cylinder head in for inspection ( pulled to fix a head
gasket oil leak......)
the guides were within spec......(no significant wear was measured.)

The head was a little sludged........from using the dino juice, but the
moral of the story
is that conventional motor oil does the job. The little sludge residue is
harmless from a mechanical
standpoint.

IMO, the by products from combustion ( acids, water etc....) are the worst
things for an engine.
I would rather change cheap dinosaur oil more frequently..... (and recycle
the oil of course!)

5w Thin Synthetic oil will leak sooner than 20w Dinosaur oil,
but the seal was going to leak anyway.......

Henri


Ed Mathews wrote:

> Hey,
>      I'm the new (and enthusiastic) '95 325i owner.  The car has 130K on
> it.  I've always sworn by Mobil 1 for all of my cars, in that after a
> few changes with it, it seems to make a noticeable difference in how
> clean the engine stays.  And I've noticed that after the 3'rd or 4'th
> change the Mobil 1 oil also seems to stay much cleaner on the dipstick.
> I've used it in my VW, Porsche, Honda, and Chevy with similar results.
> I've also always used it only after the engines had used conventional
> oil for the first 50-75K.
>      I've heard the warnings of oil seal and gasket problems in cars
> that have never used it through the Porsche list, but I've never
> experienced that, or actually ever heard of anyone who "first hand"
> experienced it, so I've dismissed it as folklore.  Now, the BMW mechanic
> (comes highly recommended - seems knowledgeable and friendly) that is
> inspecting my car tells me not to use it because he's had it cause
> problems with seals with cars that have never had it before.
>      So now I don't know whether to believe this or not.  He says
> Castrol is better than other conventional oils, and will clean and
> protect the engine as well as Mobil 1.  I've always considered most
> dinosaur oils to be pretty similar if they meet the same API rating, and
> it sounds to me like he's got a deal with Castrol.  But he is definitely
> more experienced than me with the guts of BMWs and even all cars for
> that matter.  Any thoughts?  Anybody ever really seen this mysterious
> synthetic oil seal problem first hand?  I'd really like to have a
> mechanic I can totally trust here, so I'm kind of hoping someone tells
> me they've seen the problem.
>
> Thanks,
> Ed
> http://lightandsilver.com
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