Engine Oil Filter
Study BY: Russ
W. Knize.
Warning!
These pages are NOT to be taken as gospel.
The primary motivation behind this study was to provide information about what
oil filter brands are made by which manufacturers. The secondary motivation was
to uncover some of the obvious internal construction issues of these
manufacturers. This "study" is not a "test". The SAE J806
and J1858 tests were designed to test the filtration capability of these
filters, but unfortunately they have several short comings. These include
issues such as anti-drainback valve functionality
(valve train noise, etc.), filter element containment capability (how long
before it blocks and bypasses--related to surface area), and many testimonials
that appear to point in the direction of certain manufacturers. It has been my
hope to shed some light in the direction of these issues. While my infamous
"two eyes and common sense" approach may not be the most scientific,
it is the best I could do considering there was no personal return on the
investment of time and money I put into it.
The primary shortcoming of this study is
the small sampling size. I only tested the Ford 5.0L filter. It has come to my
attention that some brand names use different manufacturers for different
applications. Another shortcoming is the lack of testing of the filter element
media itself. Unfortunately I have neither the time nor resources to do this.
I invite anyone with the means to take a
larger sampling size and conduct a more complete study, which may include
private SAE tests. I also invite anyone to repeat a study similar to this one
on other model filters.
With all of that said, please make your
own judgements. Use this study only as a source of
some information that may give you a better idea about which filter brands to
steer clear from. It should be obvious that some manufacturers are not being
honest about their product. The next time you buy a filter for your car, buy
two and hack one open to see what you have. My intent was to give you some
information and alert you to some little-known issues, not to tell you what to
think.
Description
One
weekend I set out to every auto parts store in my area and bought every brand
of oil filter I could find. I chose to
get the filter for the early Ford 5.0L V8 engine. The reason is that this is a popular filter, it is large so that I can unveil any fake miniature
internal components. I was able to
find 20 different filters spanning several brand names. They are (in alphabetical order):
AC
Delco Duraguard PF2
AC
Delco Duraguard PF2L
AMSOIL
SDF15
Car
And Driver SF-1A
Champ
Deutsch
D539
Deutsch
D545
Fram Extra Guard PH8A
Fram Tough Guard TG8A
Fram Double Guard DG8A
Hard
Driver HD01
Mobil
1 M1-301
Motorcraft FL-1A
Penzoil PZ-1
PowerFlo SL30001
ProLine PPL-30001
Purolator
Premium Plus L30001
Purolator
Premium Plus L390001
Purolator
Pure One PL30001
Quaker
State Q58A
STP
S-01
Wix 51515
Disassembly and Measurements
Basically, I cut open each filter on a
lathe and took measurements of many of their attributes. Simply cutting them open revealed some very
interesting (and disturbing) information.
The sections below detail each of the
filters I tested. A summary of the
measurements I took can be found in a table for each. I noticed that other filter part numbers for
the same brand were designed a bit differently.
This is probably because of the shape of the can and the requirements
for that engine. Here is a description
of each table entry:
Average Retail Price |
The average of all the retail prices I found
for this filter (to the nearest $0.50) |
Cartridge Length |
The length of the filter cartridge,
including end caps |
Cartridge Outside Diameter |
The outside diameter of the filter
cartridge element pleats |
Cartridge Inside Diameter |
The inside diameter of the filter
cartridge inside support tube |
Cartridge Pleats |
The number of pleats (or folds) in the
element while in the cartridge |
Cartridge End Cap Type |
The type of material used to construct
the end caps |
Anti-Drainback
Valve Type |
The valve design and construction
material |
Bypass Valve Type |
The valve design and construction
material |
Element Type |
The type of material used to construct
the filter element and the seam seal |
Element Length |
The overall length of the element when
removed from the cartridge and stretched out |
Element Width |
The width of the stretched-out element |
Element Surface Area |
The calculated surface area of the
cartridge using the above two values |
Shell Thickness |
The thickness of the metal used to
construct the filter's shell |
Backplate
Thickness |
The thickness of the metal used to
construct the filter's backplate |
Gasket Type |
The type of material used to construct
the backplate sealing gasket (O-ring) |
Hydrostatic Burst Pressure |
The amount of pressure that the filter
case can withstand for a short duration without failure. |
SAE J806 Filtration Efficiency |
See the SAE Tests section for
more details on this test. |
SAE J1858 Filtration Efficiency |
See the SAE Tests section for
more details on this test. |
The construction of the anti-drainback and bypass valves is an important feature. Many are made of nitrile
rubber. As long as they have good
sealing surfaces, they generally work fine.
However, nitrile rubber gets stiff in extreme
cold and will likely fail to seal in those conditions. Silicone rubber seals or steel valves are not
prone to this. Many bypass valves are
spring-loaded steel and work well. Some
are spring-loaded plastic and are often not molded well enough to make a decent
seal, allowing oil to leak past them.
Probably the most important value here is
the element surface area. This
determines the amount of filter media that is available to trap particles. The smaller the area, the sooner the filter
will become plugged and will end up bypassing much of the oil instead of
filtering it. More pleats in the element
does not necessarily mean more surface area (as you
will soon see). In fact, too many pleats
can end up restricting the flow too much because there is not enough space
between them to allow oil to flow.
The shell and backplate
thickness are only relevant if your engine’s oil system operates at unusually
high pressures. Even the cheapest
filters have to be strong enough for stock oiling systems, or they will not
pass SAE tests.
The SAE filtration efficiency tests are
from the manufactures, and are only available for the filters I could find the
information for.
Other measurements and values are
debatable and I will allow you to draw your own conclusions from them.
SAE Tests
All filters have to pass SAE (Society of
Automotive Engineers) tests to prove that they can truly filter out small
enough particles. There are two tests
available for automobile engine oil filters.
All filters must pass the J806 test, but the new J1858 is much more
meaningful. Currently the J1858 test is
optional. Really, it's a way for
high-end filter manufacturers to show off their great filters.
The SAE J806 test uses a single-pass test,
checking for contaminant holding capacity, size of contaminant particles
trapped, and ability to maintain clean oil.
As an amendment of the J806 test, the multi-pass test also looks for
filter life in hours, contaminant capacity in grams, and efficiency based on
weight. The efficiency of the filter is
determined only by weight through gravimetric measurement of the filtered test
liquid. Typical numbers for paper filter
elements are 85% (single pass) and 80% (multi-pass).
The SAE J1858 test provides both particle
counting and gravimetric measurement to measure filter capacity and
efficiency. Actual counts of contaminant
particles by size are obtained every 10 minutes, both upstream (before the
filter) and downstream (after the filter), for evaluation. From this data
filtration ratio and efficiency for each contaminant particle size can be
determined as well as dust capacity and pressure loss as a function of
time. Typical numbers for paper element
filters are 40% at 10 microns, 60% at 20 microns, 93% at 30 microns, and 97% at
40 microns.
AC Delco
Duraguard PF2
Some years ago, a study was done on oil
filters that uncovered the Fram filter farce. They named AC Delco’s filter to be one of the
better models. Later, AC Delco changed
their design and went to a cheaper setup made by an offshore manufacturer. Even so, I definitely recommend this filter
over the design of any Fram filter. In fact, I even recommend it over the low-end
Wix and I (personally) prefer it over the Purolators.
The filter cartridge has a large outside diameter
with deep pleats, which gives the filter element the maximum flow
possible. At first glance, it appears to
have little filter element media, but the surface area measure was suprising: 315 sqin. The unit had a solid top end cap because the
bypass valve is at the bottom, which is a well-constructed
spring-loaded steel with a nitrile seal design. The nitrile rubber diaphram-type anti-drainback
valve doubles as the seal between the bypass valve and the cartridge. The only drawback to this design is that the
bypass valve seats metal-to-metal against the backplate. This could allow oil from the clean side of
the filter to seep back into the oil pan, but it won't allow the dirty oil in
the filter to seep back. Oil that is in
the main gallery usually leaks out through the main bearings anyway while the
engine sits. This is a better
alternative to the high-end Wix, which can allow oil
to seep from the dirty side of the filter to the clean side.
The telltale signs for an AC Delco filter
are: 5 large holes for the oil inlet and
6 spot welds on the rim surrounding them.
There are no crimps holding the gasket in place. When you look through the inlet holes, you
can see the metal bypass valve with its 12 small holes and the black anti-drainback valve diaphram around
it. Through the center outlet hole, you
can see the spring for the bypass valve.
Exploded
view:
Average Retail Price |
$3 |
Cartridge Length |
4.625 inches |
Cartridge Outside Diameter |
3.375 inches |
Cartridge Inside Diameter |
1.375 inches |
Cartridge Pleats |
36 |
Cartridge End Cap Type |
Stamped steel |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel |
Element Type |
Paper media, glued seam |
Element Length |
70.0 inches |
Element Width |
4.500 inches |
Element Surface Area |
315 square inches |
Shell Thickness |
0.015 inches |
Backplate
Thickness |
0.100 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Car And
Driver
SF-1A
This
filter is a Champion filter with the one-piece filter cartridge and the fragile
paper filter element.
Average Retail Price |
$3 |
Cartridge Length |
4.000 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
54 |
Cartridge End Cap Type |
Stamped-steel, with bypass valve |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Paper media, glued seam |
Element Length |
87 inches |
Element Width |
3.875 inches |
Element Surface Area |
337 square inches |
Shell Thickness |
0.012 inches |
Backplate
Thickness |
0.102 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Champ
This filter is manufactured by Champion
Laboratories, Inc. (same guys who make the spark plugs), and is sold under
several other brand names. Champion admits
some of these outright, and they are: Lee, Lee Maxi, and STP. Though they claim the Lee Maxi is a higher
quality filter, they make no claims as to why.
It sounds more like a marketing scheme to me.
The Champion design has metal end caps on
the filter cartridge, with the bypass valve stamped right into the bottom end
cap like the Purolator. I refer to this
as a one-piece filter cartridge.
Though definitely not the same design as
the Purolator, it does use the same type of leaf-spring-type spacer at the top
of the cartridge and the nitrile anti-drainback valve, which doubles as the cartridge-to-backplate seal, at the bottom. The drawback to this one-piece cartridge is
the rather fragile filter element paper media.
It is a thin, brittle paper that rips fairly easily. It was difficult to disassemble these
cartridges without destroying the filter element. One other issue is that I sometimes noticed
some rust on the backplate of these filters. Since the rust is usually around by the inlet
holes, any loose rust would be caught by the filter.
The telltale signs for a Champion filter
are: 6 large holes for the oil inlet, one of which is larger than the
others. Only the black anti-drainback valve can be seen through the inlet holes. There are 6 large crimps holding the gasket
in place. Through the center outlet
hole, you can see the bypass valve spring.
Usually, the backplate metal is dull, or even
rusty.
Deutsch
D539
This
filter is a Champion filter with the one-piece filter cartridge and the fragile
paper filter element.
Average Retail Price |
$3 |
Cartridge Length |
4.000 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
55 |
Cartridge End Cap Type |
Stamped-steel, with bypass valve |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Paper media, glued seam |
Element Length |
88.5 inches |
Element Width |
3.875 inches |
Element Surface Area |
343 square inches |
Shell Thickness |
0.012 inches |
Backplate
Thickness |
0.102 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Fram
Years ago Fram
was a quality filter manufacturer. Now
their standard filter (the radioactive-orange cans) is one of the worst out
there. These filters are manufactured by
Allied Signal, Inc. Please do not buy
these filters. By boycotting it, we may
be able to cause some change. I have
personally had one if these filters fail and actually cause engine damage due
to bits of paper and glue floating around in the engine.
For some inside dirt on Fram filters, see this email from an Allied Signal
production engineer.
Fram Extra Guard PH8A
This filter cartridge has a small outside
diameter with a rather low filter element surface area (193 sqin),
and features cardboard end caps that are glued in place. The rubber anti-drainback valve seals against the cardboard and easily
leaks, causing dirty oil to drain back into the pan. If you have a noisy valve train at startup,
this filter is likely the cause. The
bypass valves are plastic and are sometimes not molded correctly, which allows
them to leak all the time, but they often leak anyway. The backplate has
smaller and fewer oil inlet holes, which may restrict flow, and is made of thin
material.
The telltale signs for a Fram Extra Guard are: It has 8 small holes for the oil
inlet and a thin, cheap-looking backplate, and is
currently stamped with a “2Y”. There are
5 very small crimps holding the gasket in place. If you look into the center hole all the way
to the top of the filter, you will see a kind of “button” in the end cap of the
cartridge (which looks like it's made of metal from there). This is the plastic bypass valve.
Exploded
view:
Average Retail Price |
$3 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.000 inches |
Cartridge Inside Diameter |
1.375 inches |
Cartridge Pleats |
34 |
Cartridge End Cap Type |
Cardboard |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded plastic |
Element Type |
Paper media, stamped metal seam |
Element Length |
47.5 inches |
Element Width |
4.063 inches |
Element Surface Area |
193 square inches |
Shell Thickness |
0.015 inches |
Backplate
Thickness |
0.089 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Fram
Tough Guard TG8A
Even with all the problems of the other Fram filters, this one is not too bad. Aside from the filter cartridge, it is a very
good design. Too bad Fram
can’t get passed the cardboard end caps.
It has an improved filter element with
more surface area (248 sqin), a heavy silicone anti-drainback valve with a good sealing surface, the same
plastic pressure relief valve but with an integral screen to keep out large
particles, and enough inlet holes for good flow. The only real drawback to this filter is that
it is capped on each end with cardboard instead of metal.
The telltale signs for a Fram Tough Guard filter are: It has a better backplate
that is usually shiny, with six larger holes for the inlet and 6 spot welds around the them.
There are 6 large crimps holding the gasket in place. When you look through the inlet holes, you
can see the orange anti-drainback valve. If you look into the center hole all the way
to the top of the filter, you will see a kind of “button” in the end cap of the
cartridge (which looks like it's made of metal from there). This is the plastic bypass valve.
Average Retail Price |
$5 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.000 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
50 |
Cartridge End Cap Type |
Cardboard |
Anti-Drainback
Valve Type |
Silicone rubber diaphragm |
Bypass Valve Type |
Spring-loaded plastic with integral
screen |
Element Type |
Paper media, stamped metal seam |
Element Length |
61.0 inches |
Element Width |
4.063 inches |
Element Surface Area |
248 square inches |
Shell Thickness |
0.015 inches |
Backplate
Thickness |
0.187 inches |
Gasket Type |
Nitrile
rubber, PTFE-treated |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Far Left: extra guard cartridge. Left: Double Guard. Right: Tough Guard
Fram Double Guard DG8A
This is a frustrating filter. Please do not buy it. It is one of the most expensive filters you
can buy and it is junk. Inside is a
basic Fram Extra Guard (PH8A) filter element that has
larger diameter
holes at the end and has been pre-oiled. You can see this in the picture above (far
left). I assume this is to hold the
Teflon particles in the filter element before the unit is installed. Don’t put Teflon in your engine. It does not belong there! DuPont does not recommend using their Teflon
product in internal combustion engines.
Although it has the worst filter element
possible (193 sqin), it does have a clever
spring-loaded nitrile rubber anti-drainback
valve and bypass valve combination. Too
bad the rest of the filter is worthless.
Please don’t buy this filter!
The telltale signs for a Fram Tough Guard filter are: It has a better backplate
that is usually shiny, with six larger holes for the inlet and 6 spot welds around the them.
The backplate should be
stamped with a “1K”. There are 6 large crimps holding the gasket
in place. The anti-drainback
valve diaphram behind the inlet holes is black. If you look into the center hole all the way
to the top
of the filter, you will not see the “button”
in the end cap of the cartridge (which looks like it’s made of metal from
there).
Average Retail Price |
$10 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.000 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
38 |
Cartridge End Cap Type |
Cardboard |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Nitrile
rubber, integral |
Element Type |
Paper media, stamped metal seam |
Element Length |
47.5 inches |
Element Width |
4.063 inches |
Element Surface Area |
193 square inches |
Shell Thickness |
0.015 inches |
Backplate
Thickness |
0.187 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Mobil 1
M1-301
Like the Champion, this filter is made by
Champion Industries. However, it uses a
unique end plate and a thicker can that make it the strongest filter available
for wide-distribution retail sale. It
also does not use the fragile paper media of the Champion filter. I’m happy to say that this filter is NOT a
fake. It is definitely a unique design.
It uses a synthetic fiber element that can
filter out very small particles and is much stronger than the fragile, Champion
paper media. It is rated just under the
Purolator Pure One as far as filtering capability, but is still very much above
conventional paper filters. It also has
a very strong construction to withstand high-pressure spikes during start-up. Given the choice between the Purolator Pure
One and the Mobil 1 filters, I would choose the Mobil 1 because of the
restriction concerns of the Pure One and that pesky assembly string. However, as with all Mobil 1 products, expect
to pay 2 - 3 times as much for this filter.
Exploded
view:
Average Retail Price |
$10 |
Cartridge Length |
4.250 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
52 |
Cartridge End Cap Type |
Stamped-steel, with bypass valve |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Synthetic media, glued seam |
Element Length |
85 inches |
Element Width |
4.125 inches |
Element Surface Area |
351 square inches |
Shell Thickness |
0.022 inches |
Backplate
Thickness |
0.138 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
600 psi |
SAE J806 Filtration Efficiency |
Single pass: 98% |
SAE J1858 Filtration Efficiency |
Unknown |
Motorcraft
Long Lasting FL-1A
This is an interesting filter. Basically, it is a Purolator Pure One filter
cartridge in a Purolator Premium Plus case.
Don’t be fooled by the differently-shaped holes cut into the oil
inlet. This is the only difference. This is a good filter
design and if you want to get a Purolator Pure One filter, get this one
instead: it is cheaper.
Like the Purolator Pure One, this filter
cartridge features a very large element surface area (400 sqin),
but with many pleats (64). This packs
the filter together rather tightly and may restrict flow somewhat. I could identify the Pure One element media
by a purple dye they use at the seam. It
also has the mysterious assembly string wrapped around the outside of the
element. Like the Purolators,
it features a spring-loaded metal bypass valve and a nitrile
rubber diaphram-type anti-drainback
valve. The bypass valve is stamped right
into the bottom end cap of the cartridge, so it is all one piece.
This
data is taken from the Purolator specs and are not from Motorcraft:
Average Retail Price |
$3 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
64 |
Cartridge End Cap Type |
Stamped-steel, with bypass valve |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel |
Element Type |
Paper media, stamped metal seam |
Element Length |
100.0 inches |
Element Width |
4.000 inches |
Element Surface Area |
400 square inches |
Shell Thickness |
0.011 inches |
Backplate
Thickness |
0.120 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Single pass: 99.7% |
SAE J1858 Filtration Efficiency |
Unknown |
1515 Gold
This filter is a Wix
filter with the two-piece filter cartridge.
As with the Wix filter, the metal bypass valve
seats on the metal cartridge end cap with no gasket of any kind. Some small amount of oil probably leaks
through there. It also has the tougher paper
filter media of the Wix.
Average Retail Price |
$5 |
Cartridge Length |
4.000 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
59 |
Cartridge End Cap Type |
Stamped-steel |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Paper media, glued seam |
Element Length |
87 inches |
Element Width |
3.875 inches |
Element Surface Area |
337 square inches |
Shell Thickness |
0.014 inches |
Backplate
Thickness |
0.104 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
51515 Silver
This filter is a champion filter with the
one-piece filter cartridge. As with the
other Champion filters, it has the fragile paper media for a filter
element. This is based off of my
observation of the filter’s case. I did not
purchase this filter to tear down, but may do so in the future.
Penzoil
PZ-1
This filter was a big disappointment, but
I knew what I was in for the moment I took it out of the box. It is a Fram Extra
Guard (PH8A) in every way, shape, and form. The only difference is the yellow paint and Penzoil logo. As
with the Fram, please do not buy this filter. Penzoil is
insulting their own name by putting it on this filter, but obviously they are
not interested in selling a quality unit.
All
the measurements were exactly the same as the Fram
Extra Guard PH8A.
Average Retail Price |
$2 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.000 inches |
Cartridge Inside Diameter |
1.375 inches |
Cartridge Pleats |
34 |
Cartridge End Cap Type |
Cardboard |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded plastic |
Element Type |
Paper media, stamped metal seam |
Element Length |
47.5 inches |
Element Width |
4.063 inches |
Element Surface Area |
193 square inches |
Shell Thickness |
0.015 inches |
Backplate
Thickness |
0.089 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
PowerFlo
SL30001
As you may suspect by the part number,
this filter is a Purolator Premium Plus.
There were no manufacturing differences, but the cost was an average of
$2 instead of $3.
ProLine
PPL-30001
Yet another Purolator Premium Plus. All measurements were the same. The cost was $2. One thing I noticed with this particular
example was that the mysterious assembly string was tied too tight and had
damaged the filter element. Although
only this one had the problem, I am suspicious of this filter design as a whole
(including all of the Purolators).
<- With String - String Removed ->
As you may be able to tell, the string did
not rip into the filter element, it only crushed it. There was no evidence that the element had
been compromised. Out of the 8 Purolators (and clones) tested, this was the only one with
a problem.
Purolator
Premium Plus L30001
Left
to Right: Motorcraft, Purolator Pure One, Purolator
Premium Plus
Here is a fairly well designed filter,
especially for the price. One odd thing
about Purolator’s filters is a string that is always wrapped around the filter
element. I assume that this is there to
hold the element in place while the glue in the end caps cures. Of all the
Purolator-based filter I tested, there was one (the ProLine)
that had filter element damage from this string. Although it was one of five tested, I am
weary of this design. Even though the
element was crushed a bit, it was not ripped.
I will take apart a used one at my next oil change.
The filter cartridge has an impressive
surface area of 316 sqin, which is very close to the
AC Delco Duraguard.
The difference is that Purolator's filter element is compressed into
more pleats (51) than the AC Delco. This
may restrict flow somewhat, but not as much in this model than the Pure
One. It features a spring-loaded metal
bypass valve and a nitrile rubber diaphram-type
anti-drainback valve, which doubles as the seal
between the backplate and the cartridge. Like the Champion, this bypass valve is
stamped right into the bottom end cap of the cartridge, so it is all one piece.
The telltale sign for a Purolator filter
are: 8 medium-sized holes for the oil inlet and nothing but a black (or orange
for the Pure One) diaphram to be seen through
them. There are 6 large crimps holding
the gasket in place. Through the center
outlet hole, you can see the spring for the bypass valve.
Exploded
view:
Average Retail Price |
$3 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
51 |
Cartridge End Cap Type |
Stamped-steel |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel |
Element Type |
Paper media, stamped metal seam |
Element Length |
79.0 inches |
Element Width |
4.000 inches |
Element Surface Area |
316 square inches |
Shell Thickness |
0.011 inches |
Backplate
Thickness |
0.115 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Pure
One PL30001
This filter has a few improvements over
the Premium Plus. It has a denser filter
media to filter out smaller particles and more surface area to make up for the flow
restriction. Aside from those the
cartridge is the same construction as the Premium Plus.
The filter cartridge has an even more
impressive surface area of 400 sqin. The potential issue is that this filter
element is compressed into even more pleats (64) than the Premium Plus. This may restrict flow more than it helps
relieve it. It also features a
spring-loaded metal bypass valve and a silicone rubber diaphram-type
anti-drainback valve, which doubles as the seal
between the backplate and the cartridge. The bypass valve is located at the base of
the cartridge, not at the top.
Average Retail Price |
$5 |
Cartridge Length |
4.125 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
64 |
Cartridge End Cap Type |
Stamped-steel |
Anti-Drainback
Valve Type |
Silicone rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel |
Element Type |
Paper media, stamped metal seam |
Element Length |
100.0 inches |
Element Width |
4.000 inches |
Element Surface Area |
400 square inches |
Shell Thickness |
0.011 inches |
Backplate
Thickness |
0.115 inches |
Gasket Type |
Nitrile
rubber, PTFE-treated |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Single pass: 99.7% |
SAE J1858 Filtration Efficiency |
Unknown |
QS8A
Yet another Purolator Premium Plus. Who are these people fooling? Cost was a bit over $2. If you like Purolators
and you like the color green, buy this filter.
STP
S-01
This filter is the Champion Industries
filter with the one-piece filter cartridge and the fragile paper element.
Average Retail Price |
$3 |
Cartridge Length |
4.000 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
58 |
Cartridge End Cap Type |
Stamped-steel, with bypass valve |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Paper media, glued seam |
Element Length |
93 inches |
Element Width |
3.875 inches |
Element Surface Area |
360 square inches |
Shell Thickness |
0.012 inches |
Backplate
Thickness |
0.102 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Wix
These
filters are manufactured by the Dana corporation, who
also manufactures all of the Wix clones. These include
NOTE: This section of
the page was incorrect in regards to the “low-end” and “high-end” Wix concept. What I
thought was a “low-end” Wix is actually manufactured
by Champion Industries. My thanks to
those who pointed this out to me. If you see any remaining references to
low-end and high-end Wix filters, let me know. Hopefully I found them all.
This filter has metal cartridge end caps,
but has a separate bypass valve that rests against the bottom end cap, like the
AC Delco. I refer to this as a two-piece
filter cartridge. Like the Champion, it
uses an anti-drainback valve that doubles as the
bypass valve-to-backplate seal. Instead of the leaf-spring-type spacer that
most filters use, these use a stiff coil spring at the top of the
cartridge. Like the Purolator, the
filter element paper media is stronger than the Champion media. The only drawback to this design is that the
bypass valve seats metal-to-metal against the bottom cartridge end plate. This could allow dirty oil to seep from the
dirty side to the clean side of the filter, bypassing the element. The design will not allow oil to seep back
into the pan, though.
The telltale signs for a Wix are: 6 large holes for the oil inlet with only the
black anti-drainback valve to be seen through
them. There are 6 “notches” that hold
the gasket in place. Through the center
outlet hole, you can see the bypass valve spring. Usually the backplate
metal is shiny.
51515
This filter features a good surface area,
but a lot of shallower pleats. This
makes it similar to the Purolator’s pleats.
Average Retail Price |
$5 |
Cartridge Length |
4.000 inches |
Cartridge Outside Diameter |
3.250 inches |
Cartridge Inside Diameter |
1.625 inches |
Cartridge Pleats |
61 |
Cartridge End Cap Type |
Stamped-steel |
Anti-Drainback
Valve Type |
Nitrile
rubber diaphragm |
Bypass Valve Type |
Spring-loaded steel, nitrile
seal |
Element Type |
Paper media, glued seam |
Element Length |
90 inches |
Element Width |
3.875 inches |
Element Surface Area |
349 square inches |
Shell Thickness |
0.014 inches |
Backplate
Thickness |
0.104 inches |
Gasket Type |
Nitrile
rubber |
Hydrostatic Burst Pressure |
Unknown |
SAE J806 Filtration Efficiency |
Unknown |
SAE J1858 Filtration Efficiency |
Unknown |
Conclusions
All of this information can be a bit
overwhelming. When it comes down to it, all
of the lower-priced filters ($5 or below) have they ups and downs. In reality, there are only five different
manufacturers available. Here are the
low-cost filters that I feel safe using, based on all this information (in
alphabetical order): AC Delco, Purolator, and Wix. Here are my reasons for each:
I like the deep pleats of the AC Delco’s
filter element and the fact that it is not weak like the Champion. I also like the way that the anti-drainback valve diaphram makes a
positive seal to the filter cartridge and to the bypass valve, which sort of
“snaps” into the diaphram. The fact that the bypass valve seats against
the backplate metal-to-metal is not a big deal. It probably doesn’t leak anyway, but if it
does, only clean oil can get back into the pan.
In case you haven’t noticed, I like this filter. :-) It
is the best filter that you can buy for $3.
The Purolator is a very solid design. It seems to have the toughest paper filter element
of them all and the bypass valve is built right into the cartridge. There are no internal sealing problems with
this filter at all. I wish the inner
diameter of the cartridge was smaller so that the pleats could be fewer and
deeper. The Premium Plus version looks
like it flows fine, but the Pure One or Motorcraft
versions seem to be packed a bit too tightly.
That assembly string still bothers me somewhat, but not enough to avoid
these well-made filters completely. My ‘88 Shadow ES (as
of
I don’t care for the Champion
filters. The filter elements are way too
fragile to give me much confidence in them.
That, along with the rusty backplates, makes
me shy away from them. Some decent
filter material and a little oil used during assembly would make this into a
fine filter. Like the Purolator, I like
how the bypass valve is built right into the filter cartridge. This filter has no internal sealing problems,
either. Even so, I won’t be using them.
The Wix filter
is a very well made filter. My praise
goes to Dana for putting some effort into it.
Aside from being a stronger case, it also uses a much better filter
element (about the same as the AC Delco).
Like the AC Delco, it also has a minor internal sealing problem. In this case, the bypass valve has a
metal-to-metal seal to the filter cartridge.
It probably doesn’t really leak either, but if it did, dirty oil could
get to the clean side of the filter.
Otherwise it is a good filter. Given the choice between the Wix and the AC Delco at the same cost, I'd pick one while
blind-folded. However, the Wix is about twice the
price, so...
If money is no object, I would go with the
Mobil 1. Although it has Champion
internals, it has a really tough synthetic fiber filter element, which is the
Champion’s only major downfall. The
element is stronger and thicker than the Purolator, but they claim that it
flows just as good as paper. As with the
other low-end Wix filters, it has no internal sealing
problems. The $10 price tag is a bit
steep, but it is the best filter you can buy retail. Watch for “Mobil 1 Oil Change” sales, which
includes 5 quarts of Mobil 1 synthetic oil and a Mobil 1 filter. Granted, there are probably better filters
available through mail order, but I haven't tested those yet...
I reserve the right to change my opinion
at any time. It could easily change if
another filter (or one of the filters I am waiting on) comes around and is
better.
It should be clear that Mopar filters are really nothing special. Unless you are trying to have a perfect
restoration and need that Mopar logo, there is no
reason why you should be buying Mopar oil
filters. Most of them seem to currently
be Purolators or Champions, but that could change at
any time.
See the AC Delco, Champion, Fram, Purolator, and Wix sections
for information on how to identify these manufacturers by looking at the backplate. The
tell-tale signs are always there.
Copyright © 1996-2003 Russ
W. Knize.