Special Oils

I have a 92 Honda Accord LX with 181,000 miles.

Is anyone using high milage or synthetic oils in thier high milage
Hondas. Do these oils help extend the life of your vehicle?

spaceaze

 

Always good to review this topic once in awhile.

I personally won't put synthetic into my 1991 Civic, 164k miles, because I
have read and heard reports that the synthetic's effects are destructive to
various engine oil seals.

Others say not so.

Keep checking back.

 

from what i understand, synthetic doesn't
destroy seals, but if you have used dino for a
long time, and there is a lot of varnish and
buildup on the seals, they dry out. Then, if
you suddenly switch to synthetic, the synthetic
washes away this sludge. Since the seals are
dried out due to the above, they leak.

I switched my 98 civic to synthetic at
100000kms. I have a little seapage at my oil
pan, but aside from that I NEVER have to add
oil. My car has 220000kms on it now.

t

 

My thinking is, if an older engine can handle the high revs (and occasional
redlines), without losing it's oil (or only about 1L per oil-change), the
seals are probably good enough condition to handle the synthetic oil.
However, if the older engine has never proven itself (always been babied),
switching to synthetic is risky business. Note, Mobel-1's 10W30 is a blend
is ment for older engine.

I'm not sure about the previous model Civic or Accord, but for the 96 and
up, 100000km can still be considered a newbie engine and shouldn't have any
issues with the synthetic blend (assuming the engine has undergone regular
maintenance).

Pars
98 Civic Hatch

 

Old wives' tale told countless number of times over
the internet. The problem is that the polyalphaolefin
(PAO) base oil in many synthetic oils has a tendency to
shrink seals. To counter that an ester base oil and/or
seal swelling ingredients are added.

Mobil had a huge problem with leaking with the original
Mobil 1 because they didn't properly formulate it for
seal compatibility.

The other thing is that many of the "synthetic" oils
sold today don't contain PAO, but a heavily processed
petroleum oil. Most of what's sold (in the US) as
Castrol Syntec, Valvoline SynPower, QS, Pennzoil
are known to be Group III petroleum oils. It's
debatable whether or not they're "synthetic", but they
are a higher performance than what's sold as conventional
oil. Mobil is about the only company that hasn't used
a Group III oil and packaged it as a "full synthetic".

With many older cars, the seals may be ready to leak.
Add a little bit of a PAO oil and it could shrink a bit
before the other ingredients soften up the seals again.

 

The ester *is* a swelling agent... and it's not impossible that there is
some truth to the old wives tale. I believe the branched chain paraffins
in all synthetics are somewhat more "mobile" liquids than petro basestocks.

Yeah, we *think* Mobil is still using a true PAO as the principal
ingredient - like many others, they truncated the info in their MSDSs a
while back so the only way to know is to do the analysis... which I'm not
sure anybody has done independently. BTW the hydrotreated petro-stocks
sold as synthetic claim to have similar structure molecules as the real
synthetics, so are likely to have a similar BuNa swell factor.

 

I've read that Group III base oils still don't have the performance
of PAOs, including inherent cold temp, high temp, and viscosity
index. Also - there seems to be a limit on how viscous a Group
III oil can be without VI improver. PAOs and PAO/ester blends are
reported to be available in a huge range of viscosities, although
it's probably not that important in automotive engines.

Mobil is still touting Mobil 1 as containing PAOs:

<http://www.mobil1.com/USA-English/MotorOil/Oils/Oils_FAQs.aspx#Mobil_1_FAQs3>

"Is Mobil 1 with SuperSyn Technology a fully synthetic motor oil?

Yes, it is. To meet the demanding requirements of today's
specifications (and our customers' expectations), Mobil 1 with
SuperSyn uses high-performance fluids, including polyalphaolefins
(PAOs), along with a proprietary system of additives. Each Mobil 1
with SuperSyn viscosity grade uses a unique combination of synthetic
fluids and selected additives in order to tailor the viscosity grade
to its specific application."

 

I'm sure you've also read the Chevron paper on hydrocracking and its
benefits.... with VI and other characteristics which are more or less as
good as PAOs.

Well at least they do specify PAO and one hopes they are using "synthetic"
in its true sense rather than the BBB Advertising Division adopted term to
cater for Castrol. I notice that Castrol has taken down their "confession"
page.

 

That may only apply to the Mobil 1 brand. I've heard reports that
Mobil's semi-synthetics may use group III as their "synthetic"
component.