Determining oil change intervals via analysis

I would be MUCH more comfortable if I knew that the recommendations were
coming directly from engineers, unsullied by the hands of marketing
people.

Marketing people have one goal: sell more cars. To do that, they make
the cars more attractive to the consumer. To make the cars more
attractive, they make sure they can fill a positive checklist with as
many checkmarks as possible, to compete with the next guy. One of those
checkmarks is, for example, "100,000 mile tuneup interval". Another
would be extended time/distance oil changes.

When I read the owner's manual for some of this, I have no idea if the
recommendation came directly from engineering, directly from marketing,
or is somewhere in the middle.

 

A lot of my post was tongue in cheek, poking a bit of fun
at some other posters.

The extended oil change is a marketing thing for GM. Our District
Service Manager pushes this because it looks good for GM to
be "green", make the vehicles "appear" as though they are
"maintenance free"....etc. Of course it conflicts with the dealership
in that we like to get the vehicles in more often. GM also would
be quite happy if the vehicles stay out of the dealerships, as we
end up finding all sorts of problems with the vehicles which are
still covered under warranty. GM is not that interested in fixing
problems during the warranty period.

Ian

 

Most people buy insurance to protect themselves from financial loss. I would
consider a destroyed engine a "financial loss". Therefore, if frequent oil
changes were instrumental in preventing engine failure, they would be good
insurance.

Dave

 

OK, post a reference to some real data.

Matt

 

Could be many short trips and never getting the engine to normal
operating temperature. The condensation from combustion will accumulate
in the oil over time without the opportunity to evaporate off causing
sludge. Had tis happen to a Chrysler 3.3 engine once (caused the
lifters to become oil starved). Switched to Synthetic and not a problem
since.

 

BTW: What specific engine problem would cause this to occur (except
perhaps a stuck-open thermostat)?

 

Constant short 3-4 mile trips could do it.

 

Leaking head gasket allowing coolant into the crankcase. Cracked block
or head allowing same. Many short trips in cold weather.

I don't recall there being a date at this site, but the car was
purportedly a 2001. So, if this occurred just recently, then this car
may have been five years old when the engine was torn down. 8700 miles
over five years, is very little driving. And if this was the original
oil and filter as was suggested, and if this car was driven in a cold
climate, then that would constitute extreme abuse and might well
generage that much sludge.


Matt

 

Possibly. If this 8700 miles was over a several year period, especially
in a cold slimate, then I can see this possibly happening. The site
simply has too few details to make an accurate assessment.


Matt

 

The posting of the link above misleads. Indications are that
the engine shown at the site above has an "oil gelling"
problem known to certain Toyotas and in fact resulting in a
special warranty from Toyota. See
http://www.autosafety.org/article.php?scid=&did=566 , among
other sites that discuss this.

A poorly designed PCV system is arguably the main cause.
Note the mention of the warranty at the Tegger.com site. See
also commentary at the link below from the technician who
worked on this Toyota engine. As of January, 2006, he (and
others with expertise, it seems) puts some blame on
insufficient oil changes, but just as much blame on the PCV
system, which evidently is less tolerant of low oil change
frequency compared to many other makes and models.

http://groups.google.com/group/alt....42141f52bc?lnk=st&q=&rnum=10#92e16042141f52bc


For more on oil gelling in certain Toyotas, see

http://www.carfax.com/car_safety/ra...OYOTA/model/CAMRY/trim_id/2001TOYT4DFCAMRY_LE

http://www.findarticles.com/p/articles/mi_qa3828/is_200206/ai_n9093540

 

Infernece argument? Sounds like you are used to being confronted about your
use of such tactics as red herrings. Why not direct contradiction? You
seemed to have missed the point where I told you that contrary to what you'd
like to have available as your argument, folks here consistently keep their
cars running very strong at and above 200K.

Again with the irrelevant hogwash. You are indeed proving yourself to be
well uninformed.

That you are. Too many of us here have actually maintained and driven
vehicles to that level of "high mileage used car" as you refer to it for us
to allow baseless claims to prevail. That, I suggest is the difference
between those who challenge you here and your own experiences. We've
actually done it.

 

The 7500 is for normal conditions. Hyundai recommends changing oil more
frequently for severe conditions, thus the above range. Ya, I'm a little
conservative because I never know how people treat their cars or the
conditions in which they drive.

 

1996 Accord LX, 4-cyl. 176k, uses no oil, runs like a top. Change 7500,
using Amsoil Full Synthetic.

So what are people going to do now with the new Honda maintenance indicator?
Change when the guage tells you you have 60% life left on the oil?

Stop wasting oil people. The shops ALL want you to change at 3k! hell,
they are making 3 times the money off you!

G-Man

PS, I only quote the '96 because it's the oldest car I have now, the story
has been the same for all my Hondas, and I'm on number 14 now. If I get to
250k and find out that if I had changed every 3k I could have gone to 300k,
I still feel like I won

 

[original post is likely clipped to save bandwidth]

You have absolutely no proof of that, therefore you cannot claim that.

Until you have proof, you must shut up. That's the new rule around here.[/QUOTE]


You presented is evidence in an oil change discussion. You have no
evidence it was oil change related so shut up.

gerry

 

The oil change indicator on my new Honda (2004) reminds me to change
oil every 10,000 miles. It does not indicate % life left. Honda does
not require full synthetic oil. I think that after 10,000 miles an
owner shouldn't be concerned about wasting oil by changing it. What do
you think?

 

[original post is likely clipped to save bandwidth]

Analysis of carefully collected data, sure. Wild speculation, no.

gerry

 

[original post is likely clipped to save bandwidth]

Bummer

gerry

 

[original post is likely clipped to save bandwidth]

In this conversation there is an acute shortage of data. Care to rectify
that?

gerry

 

Do you have the maintenance minder system described at sites
like
http://www.hondanews.com/catID2013?mid=2005083041013&mime=asc ?

If so, from my reading the oil change indicator does not
come on based only on mileage. A computer algorithm
evaluates engine temperatures, RPM, driving distance, and
maybe more to compute whether an oil change is needed.

 

I understand that the Chrysler 2.7 V6 has a similar problem.