Seattle Scott

Here is the first part of what I found, the rest matches exactly what you had :

<font color="#ff0000"><b>

NOTE: When reading this article, please keep in mind the date it was written and that the oil filters in question will have been upgraded and revised. Also note that this test was done by an independent European car magazine and the test results may or may not be accurate.

From: Kalalahti Matti (k124476@ee.tut.fi)
Subject: Oil filter test results!
To: toyota-l@cyberspace.cyberauto.com (Toyota mailing list),
toyota-mods@cyberspace.cyberauto.com (Toyota-Mods mailing list),
supras@cyberspace.cyberauto.com (supras),
mr2-interest@cyberspace.cyberauto.com (mr2)
Date: Fri, 7 Jul 1995 00:57:49 +0300 (EET DST)
Sender: owner-toyota-mods@CyberAuto.Com


The Finnish car magazine "Tuulilasi" compared oil filters in its latest
issue. The filters tested were all for Toyota Corolla with A-series engine.

Results in short:

Champion C138 Very good
Clean DO 851 Very good (with size reservations)
Biltema 502077 Good (with size reservations)
Purolator Micronic Good
Teho OK 174 Good (with reservations)
Fram PH 4967 Satisfactory
Motorcraft EFL391 Satisfactory
Mann W68/80 Passable
M-Filter MH 3347 Passable
Toyota 90915-10001 Inferior
Vic C-110 Inferior

"Clean" filter was was wider than others, and "Biltema" longer.

</b></font>

You showed the data but the conclusion drawn was totally different (they are all the same versus Very Good to Inferior).

Now I might agree with your theory that if you use cheap or good stuff it doesn't matter as long as you change it often enough and both are working. But that only works as long as the cheap stuff isn't failing, and cheap stuff will probably be what tends to fail. If you install a filter with an out of box defect you don't have any way of knowing unless you are testing your oil, e.g. a bypass valve is stuck open and you aren't filtering your oil at all. You wouldn't know if you installed an empty filter (a filter with no internals) just by driving around. So what do you have to "go on". Trust. And who are you going to trust? The Wal Mart special or the German / Austrian filter?

For me, what does that "trust" or perception of quality that gives me peace of mind cost? (Ignore the fact I may live in ignorant bliss) For 90,000 miles and assuming a STP filter is $3 and a Mahle filter is $10 (differance is $7)

at 3,000 intervals (30 changes) 30 * $7 =$210
at 5,000 intervals (18 changes) 18 * $7 =$126

That's pretty cheap to make me sleep easy.

Seattle Scott

sometimes called a side flow filter. You only filter about 20 percent of the oil at a time because the flow restriction is too high. They are used for really large systems where changing the fluids is just impractible to impossible and for extended change intervals.

The full flow systems we have are really pretty weak but consumer friendly and cheap.

Amsoil sells a kit you can see <a href="http://www.amsoil.com/products/bf.html" target="_top"> here.</a>

You can read about a guy that filters his oil with toilet paper <a href="http://kozmik.guelph.on.ca/gtdproject/fluids/gulf/gulfexample.htm" target="_top"> here.</a>

MikTip

The numbers are all within 2-20% of each other, varying with specific test. The closeness of the results is whats important to understand.

What the numbers actually show, is the smaller the particle, the less it is filtered!

The automotive industry drew the line at filtering down to 10 microns. The Aviation industry is at 5 micron. Hmmmmm?

If someones car suffers a catastrophic oil system
contamination, these paper filters will do very little to "save" the engine.

They are primarily designed to filter relatively clean oil, that is changed at regular intervals.

Since they all use paper as their filtering media,
their filtering performance are all relatively close together, as indicated by the test numbers.

My point being, why pay $10 for a paper media filter, when there's one available for $3? They all filter within a few percentage points of each other.

I understand the "trust" factor, but I trust the $3 filter. Been using it for years. It uses the same paper filter media as the $10 filter. I know, because I've cut both of them open.

Its for piece of mind, people are paying the extra dollars for?

The problem, I see, is when a new person comes along, they ask, "what filter do I use?" People say, "use Mann or Mahle". Now this person is paying $10 for a filter, which is no more superior in filtering than the $3 filter.

The filtering performance of a filter is whats important?

The contamination it removes is whats important?

Ever wonder why I use the larger VW diesel filter?

It has twice the filtering media as the "soda-can" sized OE filter.

Seattle Scott

within 20 percent for bypass vale activation?

After 5 minutes, % of each particle size [micrometers] filtered:
40 30 20 10

Champion 98 91 64 <b>19</b>
Vic 87 71 39 <b>4</b>

(19/4) * 100 = 475

You got me thinking about the diesel filter. It it's twice as long, with the same internal construction, all you really have is a filter that you could change less often, i.e. it won't plug as soon. The actual filtering function should be the same.

You should have a smaller pressure drop across it too, that's a good thing.

MikTip

on the air filters!

Scary stuff!