Determining oil change intervals via analysis

You're right to a point.

However, engine failures are seldom directly oil-related. An engine usually
fails from part failure or abuse long before they wear out from infrequent
oil changes.[/QUOTE]

Well, but parts can easily fail due to infrequent oil changes.

Yes, parts can also fail independent of that. That's why all insurance
is a gamble....but I reduce my gamble by buying a Honda, Acura, Toyota,
or Lexus.

 

But it is wasted money, no matter how cheap. And with synthetic oil it
isn't all that cheap.

I prefer to not pay for things I don't need. I change at 5K miles now
because it is easy to remember. I change at 10K when the warranty runs out.

I keep my cars a long, long time at 5K and 10K intervals. My minivan
had 178,000 when it was totaled and it was doing fine on 10K changes.
The reality is that you have absolutely no evidence that more frequent
changes extend engine life, because no such evidence exists,
unfortunately. I've looked for years.

We call make decisions that make us comfortable, but none are based on data.


Matt

 

Are you really going to overhaul a car engine if you see a little extra
metal? Most folks will just drive it until it quits anyway as the labor
cost is more than the parts in many cars and the consequences of failure
are relatively minor. Airplanes are a different matter completely, but
few people do preventive overhauls on car engines, even with better
information. I'd personally just run a car engine until it showed
serious signs of failure even if I had oil analysis evidence that wear
was unusually high.

Matt

 

Well, but parts can easily fail due to infrequent oil changes.[/QUOTE]

Which parts and how do they fail?

Matt

 

You are obviously not smart enough to figure that out so I will tell you in
very simple language.
It was posted to bring to your attention that there is a service available
to those interested in what is happening to the engine that is in their
chosen mode of transportation.
Is that clear enough for you or do you need a brain transplant from a monkey
to improve you intellectual capacity?

 

This should be interesting. I can't wait to see his reply... ;-)

 

Well put, Matt.

 

what is this? a stupidity contest? data abounds all over the place.
and have you ever examined a stripped motor under a microscope? i have.
wear is directly proportional to contaminant content of the lubricant.
seals don't exactly thrive when oil chemistry gets too hostile either.

bottom line: if you're trying to in some way assert that modern lubes
are better than the old stuff of our forefathers, you'd be absolutely
correct. but saying that contamination levels make no difference to
wear rates and therefore engine life is dead wrong.

 

so you've never worked in a repair shop then? what makes the ignorant
want to stand about and mock when they could get their asses on down to
a library and do some freakin' homework? "tribology" is your word of
the day. look it up.

 

Yes, and you are currently winning.

OK, show me the data. Show me the graphs of contaminant levels vs.
engine life in miles. Show me that oil changes at 3,000 miles vs.
10,000 make a difference. Put up or shut up.

Matt

 

Just as I thought. No data, just smoke screen.

Matt

 

Which parts and how do they fail?[/QUOTE]

http://www.tegger.com/hondafaq/sludge/cleaning_sludge.html

 

This should be interesting. I can't wait to see his reply... ;-)[/QUOTE]

http://www.tegger.com/hondafaq/sludge/cleaning_sludge.html

 

But it is wasted money, no matter how cheap.[/QUOTE]

Not if it takes the most expensive part of your car easily from 100K
miles to 200K miles.

Of course, since most people switch out cars every 36K miles anymore,
most people don't think that's important.

 

I prefer to not pay for things I don't need.[/QUOTE]

So you have no homeowner's insurance? No car insurance? After all,
your house will never burn down and you don't ever plan on getting into
an accident, therefore you don't need those things.

 

http://www.tegger.com/hondafaq/sludge/cleaning_sludge.html

 

no matt - you're the one making the assertion that it makes no
difference. i know it does because i've done fleet testing. i think
where you're getting confused is reading glib little articles on the net
that cleverly avoid the distinction between phrases like: "wear is
reduced" and "wear is within acceptable limits". the difference is
huge. sure, wear at extended intervals /can/ be within acceptable
limits, but that doesn't mean that sorter intervals don't reduce wear
rates to a lower level.

 

t-r-i-b-o-l-g-y matt. read about it.

 

http://www.tegger.com/hondafaq/sludge/cleaning_sludge.html

 

Correct. But again Jim, this is a red herring. None of the participants in
this discussion have denied the fundamental and quite obvious truth of your
statement above. All have only talked about the intervals that can
realistically - based on real world experiences, be achieved. There is a
lot that can be hyped in the name of Fear, Uncertainty and Doubt (FUD), but
time tested truths stand up every time.

No one said that so it becomes irrelevant to the conversation. Time has
consistently proven that the change schedules and the oil and filter
combinations talked about here, do indeed work. People are not reporting
engine failures. Quite the contrary, people are reporting engine lives
approaching or exceeding 200,000 miles. For most cars manufactured here or
across either ocean that's plenty good enough. Other parts of the cars wear
out by then, making them targets for junk yards or winter rats, or the
owners simply feel they've gotten enough out of the car and it's time for a
new one. What more could anyone really ask for?