Zach,
I've heard that too.
Another bit of anecdotal experience---my TD engine was rebuilt a few
years ago and run in on dino oil. Although friends who are wildly
enthusiastic about synthetic kept urging me to use it in the TD, I held
off until this spring. Mobil 1, 15-50 is in there now, and it seems to
be staying in there better than the Castrol 20-50 I had been using. It's
hard to measure leak spots in the cat litter in the pan on the floor, but
the estimated leaking judged from the dipstick is that consumpion and
leakage are both reduced. That's wishy-washy imprecise, since I check
oil every time I run this engine and will add a 1/2 cup or so as needed.
But it --seems-- to me that there is less staining and that I'm topping
up less frequently.
It's said that the basis for the concern about extra leakage was
similar to that concern when detergent oils came into the market years
ago. It's said that the detergents dissolve those fine accumulations of
solidified oil that provide sealing in the old engines. True? Untrue?
Hard to say for sure. Those considering synthetic oil need not worry
about uncontrolled leakage, however, if they have been using modern oils
and changing regularly.
When I start the engine, if it hasn't been run in more than a week, I
spin it on the starter until the oil pressure gauge flickers. Although I
can't measure the rpm at starter motor speeds, it seems to turn slightly
faster, and the valve click seems less than with dino oil, as if the
Mobil 1 is slipperier and it stays on the valve mechanism better. Not
having examined for oil retention with old oil and with the synthetic, I
can't say for certain, but that is my impression.
Bob
On Fri, 30 Jul 2004 08:22:14 -0700 (PDT) Zach Dorsch
<herr_dorsch@yahoo.com> writes:
> Something that I have heard about synthetic oil in an old motor is
> that it will start leaking oil due to the synthetic cleaning so well
> and be so "slippery". Has anyone else heard this or actually seen
> this happen?
>
> I ask because I have thought about switching to synthetic because my
> car sits so long (usually several months or more). I assume that
> the synthetic would not break down and help reduce wear on startup.
>
> Zach
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