dead right - my buddy's p.o.s. jag leaks because it's a jag and it has
stupid things like leather "seals". not because he runs synthetic oil.
but that said, modern seal conditioners are an important part of an
oil's additive package. on an old vehicle that has been neglected,
seals can become hard and inflexible. cutting corners [motorcraft] will
lead to seal hardening and significant leakage in that situation. and
using an oil with a good additive package can seal that puppy right back
up again, provided of course the car was any good in the first place.
it's on the web, so it must be true?
some other guy said it so it must be true?
retard. all you're doing is standing about in a circle eating the
excrement of the guy in front of you while the guy behind you eats
yours. it doesn't to teach you a damned thing except how to eat that
stuff and get brain washed into thinking it does you good.
bottom line, /you/ should avoid polluting usenet with your regurgitated
TYPO. I left out a zero.
That "20K" was supposed to be TWO-HUNDRED-THOUSAND.
The engine now has 380,000 miles. That's three-hundred-and-eighty-thousand,
in case I make another typo.
OK, not all GM. Fair enough. But those are all allegations made in Internet
posts. Nobody has verified them. It's entirely possible the posters are
blaming their oil for problems that had entirely unrelated origins.
Anybody can post to the Internet/Usenet, and anybody does. Including me.
Synthetics are completely compatible with all mineral oils. Synthetics are
suitable for new engines, ancient engines, and all engines in between.
Synthetics do not cause oil leaks through /any/ mechanism. If somebody was
using a mineral oil, switched to synthetic and discovered an oil leak, it
was a coincidence. The leak was bound to happen anyway.
Just because "A" follows "B" does not mean "A" caused "B".
There are a lot of silly ideas floating around the Internet and Usenet, and
this synthetics-and-oil-leaks thing is one of them.
Mobil 1 is 100% synthetic.
Boy does it buy you a clean engine. 180K after that head job, the head is a
sparkly-silver as the day I got hit back. I am frankly astounded.
to some extent, that's true. but there's a lot of detail missing in
that broad brush picture. fact is, detergent isn't the only thing
keeping the engine clean - it's what kind of viscosity improver [which
breaks down over time and causes deposits], and what kind of base oil
[which breaks down over time and causes deposits] too. even detergents
are different from oil to oil, not to mention anti-oxidants,
anti-foaming agents, extreme pressure additives, etc. so while paying a
lot of money for a "boutique" oil doesn't guarantee high quality, /not/
paying definitely ensures you're going to get lower quality and thus
will have to pay closer attention to the factory maintenance schedule.
no they're not. and seal efficacy is not just a function of the seal
material - it's design and also shaft finish quality.
regurgitation and failure to observe fact doesn't make for authoritative
analysis. "sludge" does not close a sliding seal any more than gravel
prevents your roof leaking.
what do you think a modern "synthetic" actually is? i'll tell you -
it's simply a slightly more refined mineral oil than is traditional.
and i know that for fact from a senior exec at one of the oil majors.
modern "synthetic" is more a label for what the oil /doesn't/ contain
than anything else.
most of the domestic "synthetics" are the same kind of group III mineral
oils as mobil 1. so don't single it out as being any worse than the
others. indeed, its additive package is very good.
at this point, it's not about the base, but the additives. premium
"synthetics" contain premium additives. on that basis, and the fact
that their additives permit sustained operation/longer drain intervals,
they're worth the money. some even have better friction reduction which
saves you their premium price in reduced gasoline consumption.
In short, summarizing the other posts - I guess you can skip the
midway oil change ANYWAY, and certainly if you switch to synthetic,
which would still see a change every seven months or so.
But, are you burning any oil with the old engine? If so then you will
have to remember to check it and maybe top it off, and what's more you
may actually be polluting the oil faster than a younger car would and
this might make your current plan the best.
I do burn about a quart of oil between current oil changes at 3,750 mile
intervals. So I replenish that much during that time span.
By the way, I happened to talk to a mechanic about this issue after I
posted my message and he said that even if the synthetic oil could allow
me to skip that "mid-term" oil change, one oil filter could be a problem
for 7,500 miles. Hm, it never even occured to me and so far none of you
mentioned itt either. It sounds reasonable though, but what do I know?
the reason nobody mentioned it is because it's not an issue. when you
have cars with 10k or even 20k mile oil change intervals, filter
clogging is rarely an issue. a honda with a modern multi-million dollar
maintenance minder wouldn't tell you to change the filter more
frequently than the oil, and honda's conservative oil management will
typically last 7-10k miles. how could any special departure from that
just for the filter seem "reasonable"?
Maybe the kind who knows the whole engine is pretty loosey-goosey
burning a quart every 3,750 miles? Reminds me of my old Alfa, where
you had to dump the oil into the gas tank every fillup. Ah, the old
Cuz he's in a much older model?
I'll leave it to you experts to judge whether and how you want to use
synthetic oil in a car burning it at that rate, my guess is - you
that doesn't burn filters though dude. if anything, the fresh oil being
added keeps it healthier - things like the drain-back valve don't become
so inflexible and the fresh detergents keep the fine particles from
doesn't matter. the 94 has a very good engine management system - it
certainly doesn't load a filter in only 3.75k miles. not even 7.5k miles.
since most car "synthetics" are in fact just "group III" mineral oils,
and most "ordinary" oils are now "semi-synthetic", most of the
differential advantages are substantially eroded and really just down to
the additive package.
but those additives can be markedly different. some oils without good
seal conditioners [motorcraft brand] will let shrink seals like crazy.
others like castrol gtx have good seal conditioners, but as tegger
relates regarding deposits, is less good for detergents. bottom line,
good branded "synthetics" are indeed good oils with great additive
packages. and if synthetics are used, it's completely pointless
sticking to the traditional oil change intervals.
as for oil burning, i wouldn't hesitate to use a synthetic in a burner.
my experience is that with the good detergent package actually
cleaning the engine, the rings tend to free up and consumption can drop
significantly. my 89's engine was burning at the rate of a quart per
thousand when i first got it with 105k on the clock. after about 2
years of synthetics, the engine had cleaned to the point you see in that
flickr pic, and today, the oil consumption rate has dropped to about
half a quart per 5k miles.
not true. in the old days of ester-based synthetics, that was more of
an issue, but these days, most "synthetics" are just refined mineral
oils so there is no shrinkage to start with, and on top of that, they
add seal conditioners. at this point, it's just an old wives tale.
if you read the wording more carefully, you'll see the difference
between the headline and the legal c.y.a. but the reality is most
synthetics can extend change intervals substantially.
contamination is what the filter is for. unless you have a low grade
filter that starts to internally leak, contamination isn't an issue
because particle size is kept below the oil film thickness size - and by
some margin too.
if you're sticking to factory change intervals. and are using a decent
quality standard oil. [most standards are semi-synthetic now anyway.]
but if you use extended intervals, which you can, synthetics are a
Quality control of filters is becoming lax these days as well... search
Google and YouTube for numerous examples.
A shorter change interval will help minimize wear should you happen to
get a bad one.
Note this passage excerpted from an 08 Honda 'Fit' owners manual:
You may use a synthetic motor oil if it meets the same requirements
given for a conventional motor oil, it displays the API Certification
Seal, and it is the proper weight. You must follow the oil and filter
change intervals given in the maintenance schedule."
that's called "cya". it's also called "if we don't spell something out,
some people will never change their oil at all". and i know that for fact.
it's also covering a situation which is a marketing reality - which is
that the word "synthetic" doesn't mean a damned thing. if something
sold as "synthetic" is in reality just a standard oil and not capable of
extended service, honda would be in for a whole bunch of unnecessary
warranty claims that weren't their fault if they didn't cya.
but if you use a quality oil, with analysis, you can use real data to
extend your service interval successfully.
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