Honda appears to have recently (late 2003) undertaken a revision
of
their oil filters and this has sparked some debate about whether or not
the new ones are as good as the old.
New filter part number: 15400-PLM-A02
Old filter part number: 15400-PT7-006
The fact that the new one appears smaller is of some concern,
especially since a smaller can may mean less filtration medium. I
decided to find out for myself some of the differences:
1) Is there less filtration medium?
2) Are there any other changes?
As a preamble, I have no connection with Honda Canada Inc. or Honeywell
Consumer Products Group. My interest in this matter comes from being a
Honda owner since 1991, and from having the desire to see my car last
as long as possible in the best shape possible. I use Honda Canada
Inc.'s FRAM-built filters because I like using OEM parts. I've had too
many bad experiences with aftermarket parts to trust them without
reservation.
Would I use FRAM's aftermarket products? Maybe the premium ones, and
only if they greatly resembled what Honda trusts to go on their engines.
Not being an automotive engineer, all I can really do is pull the
things apart and look for obvious physical differences. I have no way
of testing filtration media, spring pressures, gasket sealings, etc.,
reliably to see if anything is actually less effective from new to old,
as opposed to just looking less effective.
Paper (which is part of my native industry) is more a chemical soup
than it is
wood or cotton fibers. These days they do not simply grind up some wood
and press it into a sheet. Since the thing that ultimately makes a
filter is the filtration medium, it is critical when judging the
effectiveness of any filter to be able to apply proper tests, among
them some that
involve cycling through the filter a quantity of liquid containing a
known weight of contaminants, and measuring the difference before and
after. Just the fact that there is less medium than before is not
relevant in-and-of-itself. Since we cannot apply proper test
procedures, I will do my best with what tools I've got.
FRAM manufactures these filters according to Honda's specs and
requirements, which may or may not coincide with any of FRAM's usual
production standards, procedures or materials. Remember too that Honda
must honor any warranty claims that arise from engine damage due to the
use of its filter. Honda has only a few filters for their entire fleet,
some of which fleet will always be under warranty at any given time.
They have an incentive to ensure that the filters will function
properly within normal operating parameters.
So keep this in mind while reading...
The
filters(back to top)
Here are the cans, side by side, new one on the left. All the
pictures
in this sequence always show new on left. You can click on the pics for
a somewhat bigger picture. Both filters were sold to me for use with my
1991 Acura Integra. B18A1 engine.
They're both made by FRAM, of course, and sold by Honda Canada Inc.
Their heights are closer than they appear:
New: 3-3/8" high by 2-11/16" diameter.
Old: 3-3/16" high by 3-3/16 diameter.
The new one's slightly taller, but a lot skinnier.
Actual can capacities are 9.5 oz for the new, 12 oz for the old. The
new one is 20% smaller. I filled each can with water after cutting it
off flush with the baseplate, and poured that into a measuring cup.
I used a Dremel to cut the tops of the cans off. In the picture
below,
the filtration elements were taken off the baseplate (see lower down
for
pics of them). The orange thingies are the anti-drainback flaps.
They're made of silicone rubber, like FRAM's premium aftermarket
products. This is what prevents the oil from running back into your oil
pan overnight.
(In case you're wondering, oil flow is IN the ring of small holes under
the orange flap, through the filtration medium, and OUT the big hole in
the middle.)
The paper element would ordinarily slip over the top of the drain-back
flap by 1/8" or so. There is some pressure exerted by a metal "spring"
at the top of the filter. When the can is crimped closed with the base
plate, The element is squeezed between the top "spring" and the
anti-drainback flap, sealing it.
Notice that the new filter has dispensed with the little metal sleeve
that used to be on the old flap. It looks like there is a tapered "top
hat" on the new flap that goes into the center hole of the element.
Flip the drainbacks over, and what do we find? If you look
closely at
the old one, you'll see the the perimeter (the sealing edge) has a
ridge that the new one lacks. The new one's edge is much more flexible,
and almost tapers to a point at the perimeter. My guess is that the new
one would seal better, especially with lighter synthetic oils now being
specified by Honda for their new cars.
See the ring of inlet holes on each base plate?
New: There are ten 5mm
holes
Old: There are eight 6mm holes.
The
available oil-passage area is therefore:
New: 157 square millimeters
Old: 151 square millimeters
That's a 4% difference in favor of the new one.
The new filter has only three threads in the baseplate's big outlet
hole to hold it to the engine, while the older one has five. The new
filter takes 8-10 ft. lbs. to tighten it, while the old one takes 15-17
lbs. I was told there had been some complaints about leakage with the
old filter due to insufficient tightening, especially in the winter.
These are the "paper" filtration elements, with the bypass valve
still
installed in the metal "spring" and pushed into the top hole of the
element. This "spring" does two things: It houses and seals the bypass
valve and seals the element against the drainback valve.
As stated several paragraphs ago, if you reassemble the filter's parts,
the can will sit high about 3/16" over the baseplate until you push it
down against this top spring to seat it. Note that these FRAM elements
have "paper" end caps. More about that later.
If the element gets plugged, oil pressure will push open the bypass
valve and allow oil to flow directly to the big hole in the middle. At
that point, your engine reverts to 1920s-style unfiltered lubrication.
The bypass valve pushes open towards the engine block. That
spring is
pretty strong. The bypass valve itself appears to be the same in both
filters. It's some kind of very strong, hard plastic. Apparently the
reason FRAM uses this instead of a deformable rubber gasket is because
gaskets can come loose, disintegrate, shift and develop leaks for these
reasons. The hard plastic does none of that. Both my samples were a
perfect seal against the metal as far as I could see.
In the first pic, we're we're peeking down the element itself.
You can
see the perforated metal sleeve that keeps the filtration paper from
getting sucked through the big hole should the worst happen and the
"paper" begin to buckle under the oil's pressure. In the second pic,
the
sleeve has been removed and the top end-cap has been cut off with a
utility knife.
The sleeves are identical in both filters except for length.
Contrary to some alarmists elsewhere
on the Web, paper is not oil
soluble. It will not disintegrate if left in the engine too long (it
may clog, rip, and shear, but not disintegrate). Paper
is WATER soluble. If you ever see a sheet of paper become weak and fall
apart when soaked with oil, it is NOT because the fiber bonds have
dissolved, like they would with water, but because the paper has not
got enough fiber to withstand the weight of the oil, and because the
fibrous construction and the chemical soup which created the bonds are
not strong enough to avoid tearing. Simply, it's not designed for the
task.
Furthermore, filter makers buy
gasket-type "paper" for the end-caps and
filtration "paper" for the medium. These "papers" are NOT the same as
photocopy paper or corrugated shipping box paper. They are designed to
be immersed in pressurized oil. The same end-cap "paper" FRAM uses is
used for other gasket-type applications throughout your engine. You
have dozens of them all over the place, not just in your filter.
Also, the metal end-cap/"paper"
end-cap question is another thing is
used
to cause alarm among users. Whether a filter has metal end caps or
"paper" ones is of no consequence at all when the filter is used in its
correct application. Whether metal or "paper" is used
for the end caps, glue is still used to hold everything together, and
the glue seams (and medium pleats) are the weakest points of any
filter.
If a particular filter medium has
few pleats, more stress is placed on
the end caps and on the glue seam between the end cap and the medium,
so there would be a greater tendency for separation to occur. According
to Internet Wisdom, FRAMs are particularly susceptible to this. Low-end
FRAMs have large gaps between the pleats.
I've been told that if a particular
manufacturer is using metal end caps, it is more
probably because either 1) That's what their machinery uses, or 2) They
use the same end cap dies for industrial filters that are intended to
filter water-based liquids. NOT because "metal is better". They may
market "metal is better" if they perceive some sales advantage to doing
so, but there is no functional advantage to metal. However, it does
keep them from having to upgrade their machinery...
Now we come to the crux of the matter, the filtration medium
itself.
And all I can do is measure and observe. Both papers appear identical
to the naked eye. They both mike .040 inch in thickness.
As I said earlier, I have no way of testing the "paper" to see if there
are molecular differences, or differences in fiber construction or
layout, that might make a difference in fitration.
"Papers" can be--and are--treated with materials that impair the
paper's
ability to absorb water. If a car is driven infrequently, or for many
short trips, water begins to build up in the oil. Should the amount of
water get past a certain point, it begins to emulsify with the oil,
leading to sludge. Further, it could begin to dissolve the filtration
medium, assuming it were unprotected against water absorption, allowing
loose fibers to migrate into the engine.
Accordingly, I weighed both papers dry, soaked both papers in water for
2-1/2 hours, wiped off the exess water then weighed them wet.
I rubbed both dry papers onto a black sheet to see if any fibers could
be induced to come off the medium. A few fibers did let go from both
under the abrasion. I wouldn't think that these fibers would be
harmful, as paper is far softer than metal, and in any case they would
be trapped by the medium after a single circuit through the engine.
New filter's paper: 2-5/16" x 50-1/8", or 0.80 of a square foot.
Dry weight: 0.375 ounce.
Wet weight: 2.0 oz.
Old filter's paper: 2" x 72", or 1.0 square foot.
Dry weight: 0.5 ounce.
Wet weight: 3.0 oz.
Interesting. The papers appear to be the same density, and the
new filter loses 0.20 of a sq. ft. in area. That's a square about
5-1/2" on a side. (The new element is at the top of the pic).
The new medium increased in weight by 5.33 times when wet and the old
increased by 6 times, about 20% difference, in keeping with the 20%
differences found elsewhere. All the water ingress seems to have been
through the cut top and bottom, and through the fold lines. The uncut
faces appear to have absorbed negligible amounts of water. Tear
strength does not appear to be much reduced when wet. Also the wet
"paper" STINKS!
I think the "paper" is the same stuff in both filters.
What conclusions can I come to about the new filter?
The can is smaller, 80% of the old
one, so may take slightly less
time for
the engine to build pressure on a cold start, when the center pipe
would be dry.
The drain-back flap is more
flexible and appears to work better,
probably in response to the use of the new 0W-20 part-synthetic engine
oils Honda is specifying now.
There's 20% less filtration
medium. Is the new stuff better at its
job? Don't know. Does the loss of 20% make any difference? Don't know.
Was there more medium before than there really needed to be? Don't know
that either.
It's easier to achieve correct
tightening torque with the new
filter, so leaks should be more easily avoided.
Honda is installing these filters
on cars that are under warranty.
That should say something right there.
