Date: Fri, 21 May 1999 08:23:31 -0700
Reply-To: "Michael A. Radtke" <m.radtke@ELM.AZ05.BULL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: "Michael A. Radtke" <m.radtke@ELM.AZ05.BULL.COM>
Subject: Re: My First Oil Filter Failure
Karl said:
"The Fram actually IS freer flowing, as the filtering media is
thinner, as well as having less of it than a Mahle.
>In that case no conclusion can be made about which is a better
>filter, but it's easy to conclude which is more annoying to use.
HUH??? Which is better? Mahle by a HUGE margin. Have you not read the
recent postings re: Fram filters, or the recent test of all
aftermarket filters?"
Karl,
I have pleaded ignorance before, so please don't be impatient with me!
First, the fellow who did the filter comparison is heavily biased against
Fram. So, his reports are a bit difficult to dig the facts out of (for me)
when he speaks about Frams. He does not seem to be emotional about the
other filter brands.
Addressing just the issue of flow, I don't see how using less and thinner
filtering material affects flow unless compared with exactly the same
filter media, only thicker or more of it. While it appears that more is
better, that just may not be true if the materials are different.
Even if the material used in two different filters is the same, and differs
only in quantity and thickness, it still isn't clear to me that more is
better. As more material is stuffed into the can less of it gets in the
flow path of the oil. I believe that the oil flow tends to collapse the
pleats of the element which increases pressure which collapses the creases
further:
/\ /\ || ||
\ / | |
\ / -> | |
V \______/
From that I might conclude that freer flowing is better.
My point is that I believe that few people are qualified to predict the
performance of an oil filter by looking at it. Sometimes the "obvious"
things may not be so obvious. What I'd really like to see is a comparison
of filter effectiveness by looking at the oil in a significant population
of cars using different oil filter brands.
So, partially based on the pre-German report, I bought Purolater filters
for my cars. After reading the German filter report, I could conclude that
I made a bad choice based on filter element size. In the Mopar study,
Purolater was above average in element size, in the German study it was one
of the smallest.
So, after all of this palaver, still all I am sure of is that after 35
years of driving, I have had only one clear oil filter failure, and that
was with a contemporary Fram.
Thanks,
Mike