Oil 3.0 V6 again

When breaking in a new engine for the first 25-50 hours or so, a
non-synthetic oil is probably best, at least until the rings are seated.
But some cars today come with synthetic from the factory, so go figure. I
assume however that the initial oil the factory uses for checkout is still
non-synthetic.

 

Yes, I may not have given sufficient consideration to the language
challenges he faces, but I certainly wasn't making fun of his
nationality. I was only talking about his knowledge of oil!
I have no tolerance for racists.

Thanks, Bill.

 

I'm not aware of any such parameter for cars. I'm not saying there
isn't such a limitation, I'm just not aware of one. I am aware of an
issue that Mobil had when it introduced synthetic oil to the aviation
market. Avgas still has a fairly high lead content. The synthetic did
not suspend the lead nearly as well as mineral oil and the lead
precipated in the form of a pasty sludge. This clogged up the passages
in the controllable pitch propellors among other problems. Mobil ended
up rebuilding several fairly expensive engines and pulled the product
from the market. So, I agree with you that saying synthetic is superior
in every way is a bit over the top.


Matt

 

Yes, I should have said ethnic slur. Same difference.


Matt

 

Point taken.

Matt

 

I read somewhere that there are at least some engineers in Detroit who
believe that with today's better machining and metallurgy, the
traditional break-in period is essentially not needed. Apparently, some
engineers in Germany feel the same way as they also ship new cars with
Mobil 1. Either that, or they are doing some break-in time on the
engines before they are delivered to the customer.


Matt

 

What you say may be true, but I was not referring to any break-in
issue. What I was referring to was studies done some years ago on long
term (fleet IIRC) use of synthetics - what was discovered was that there
was a definite piston scuffing phenomenon that did not typically occur
with conventional motor oils, and it was found that a blend had a
synergisitc effect of eliminating or greatly reducing that problem
without greatly compromising the benefits of synthetics.

Now, it also may be that the manufacturers of the synthetics have solved
that problem with process or formulation changes over the years. If I
were to use synthetic, I would make my own blend - maybe 2 non-synth to
3 synth (or possibly 1-to-4) because, with the suspicious lack of info.
from the manufacturers on their blended products, and knowing how
business operates, I do not trust them to not provide a 95-to-5 blend
(i.e., just enough to legally call it a "blend") and charge a 25-to-75
price (i.e.,
perception/hype/what-the-customer-doesn't-know-won't-hurt-them vs. real
value) as a real profit niche.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

If this was a fleet test, then likely these were also diesel engines.
Not sure that would make a difference, but it might. Let me know if you
find the study again as I'd be curious to see the details.

Matt

 

Hi!

Thank's for all of Your's answers. I'll take it under a consideration.
Probably the biggest problem will be to buy set of gasket to the engine
if I would use the sythetic oil. My local mechanic says about semi one
but I don't think he is a good one. So, thanks again!

proxy

 

There is no break-in period anymore, not with cars in Europe anyway. I had
some trouble getting used to this but I am assured there really is no need.

DAS

 

I think more to the point, there are now NON-synthetic oils that show
lower metal-removal rates in oil analysis than synthetic oils do, so
saying "use dino oil during break-in" is a bit meaningless. "Break-in"
is still a very real and measurable process regardless of what
advertising glossies say. It never has really demanded all the special
treatment that has been hyped about it,at least not since the days of
cast-iron pistons in the 30s and 40s, but all engines do go through a
break-in process that really extends to about 10,000 to 15,000 miles.


As a side note, metallurgy and machining as it pertains to the wearing
parts of engines really haven't changed nearly as much as most people
might think since the mid 60s, if you look at the clearance and finish
specifications they are essentially the same then as now with a few
exceptions. Even though cylinder blocks are now predominantly aluminum,
sleeves are still nickel/iron alloy and rings are iron, chrome, or moly.
One thing that HAS happened is that some manufacturers (Chevrolet
division engines from GM for one example) are using hypereutectic
pistons with very short skirts, which demand a much tighter fit in the
bore than traditional cast pistons. The short skirts reduce friction,
and the hypereutectic material expands very little allowing (NEEDING, in
fact) a much tighter piston-to-cylinder clearance. However, it seems
that hypereutectics are so demanding in fit that quite a large
percentage of mass-produced engines leave the factory out of spec and
have audible piston slap. But rings and cylinder walls, bearings and
crankshaft journals are still very similar to what they've been for 40
years. Its a very mature technology, oils have changed FAR more than
engine materials.

 

Matthew S. Whiting wrote:

Many aviation engines are very different beasts than car engines. Silver
based bearings are still commonly used, and automotive motor oil will
make short work of them, among other problems.

 

I *think* I remember some testing that indicated that synthetic wouldn't
cling to vertical surfaces as well, and that caused excessive wear in
the thrust bearings on some engines. But that was an old, old, OLD study
from when Mobil 1 first hit the market, and I don't think it has any
bearing on modern oils at all.

 

Which non-synthetic oils?

Matt

 

It must be a pretty minimal difference as my Grand Voyager is
approaching 150K miles on Mobil 1 with no apparent problems.


Matt

 

IIRC, at least one of version of Castrol GTX and (believe it or not) one
Pennzoil formulation are turning in great numbers that are comparable to
and sometimes better than synthetics. A few others too. You can hunt
around on bobistheoilguy.com and see some of the analyses that people
have posted there to be sure, I haven't spent an afternoon wading
through all the info over there in several months

 

That rings a bell. The no clinging to vertical surfaces would go along
with poor film retention. We may have read the same thing - time frame
(early Mobil 1 years) would be about right - my teenage Popular Science
reading days.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")

 

Any idea if this was an issue simply of the viscosity of synthetic being
lower when cool thus allowing the oil for drain off the vertical
surfaces more quickly, or is it a more fundamental chemistry issue? I
haven't heard of this being a problem anytime in recent history. I
wonder if it was a real issue that was corrected, or just another of the
urban legends about synthetics, like leaking seals, etc.


Matt

 

It is more than viscosity - more to do with surface tension or
whatever - Regular oil is "wetter" than synthetic so it tends to cling
to the surface rather than bead upand slide off. At least that's how
it was described to me.

 

Hey - it was in Popular Science, so it must've been true, eh? 8^)

Seriously - I'm not sure. These were supposedly engines that were used
in real-world severe conditions (fleet or taxi service IIRC - to speed
up the results) with non-synthetic controls. Study and teardowns
performed by supposed lubrication experts, article included photos.
That's all I remember.

Bill Putney
(to reply by e-mail, replace the last letter of the alphabet in my
address with "x")