Oil Filter Comparison/Evaluation

Morfoot wrote: This is a set up right Pete?????  I'm not falling for it!!!!!

8122pbrainard wrote: So Tim, what brand filter and what oil did you recommend?

Guess that's what happens Tim when you have time on your hands waiting in line for gas 

I noticed the table images disappeared over the years. Here they are again.

OK, Steve K and I cleaned up a few technical details and have the oil filter grades.


These rankings are from the one referenced study only.

We are assuming the individual category grades (filtering, quality, etc) are common across a manufacturer's sizes of a specific filter, because the part number used in the study is not necessarily the one for our engines. For example, the different Fram filters in the study are delineated by application ("High Mileage", "Racing", etc), whereas we're referring to different filter sizes within an application type.

These rankings do not factor in price (on purpose).


The updated table follows. Five filters get an A- or B+ for their final grade. There are a lot in the middle grades, and a lot in the low grades.

I'm switching to Mobil 1 oil filters.

Steve





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This is essentially the logic train I used. Now that's not to say there is an error in one of my formula's...

IF(D4="A", 4, IF(D4="A-", 3.75, IF(D4="B+", 3.25, IF(D4="B", 3, IF="B-", 2.75, IF(D4="C+", 2.25, IF(D4="C", 2, IF(D4="C-", 1.75, IF(D4="D+", 1.25, IF(D4="D", 1, IF(D4="D-", .75, IF(D4="F+", .25, 0)))))))))))

Steve K,

An excellent project, thank you.

I have a question about your weighted averaging in your April-22-2013 10:29pm post. The best scoring filters are:

FILTER: grade FILTERING/QUALITY/surface/volume
K&N HP-3002: grade 3.88 B/A-/b+/a
Fram Xtended Guard XG5: grade 3.81 A-/A/c/a
Mobil 1 M1-302: grade 3.73 B/A/a-/a
Wix (NAPA) 51060: grade 3.42 C/A-/b+/b+
Purolator Pure-one PL34631: grade 3.42 C-/B+/a-/b+

Look at the individual grades... The Mobil 1 B/A/a-/a is better than the K&N B/A-/b+/a, so the Mobil 1 should have the higher weighted grade, correct?

I was unable to match the grades values you received. I assume you multiply the weighting times the grade, add, then divide by the weighting total (12). Example: Mobil 1: [5(3.00)+5(4.00)+1(3.67)+1(4.00)]/12 = 3.56, but you get 3.73. Am I miscalculating this?

Another question: Are all the oil filter part numbers you list for the PCM 351W? I haven't looked any of them up.

Thanks, I love this kind of study. I know, I'm a geek...

Steve

Funny thing about filters, every part number is built different to different specs as specified by the engine manufacturer. Motorcraft FL-12, is not the same as FL-1-A, or FL-820-S, etc. Same thing can be said about the price, common filters like FL-1-A or FL-820-S are way cheaper and easier to find than a FL-12. Who buys a Motorcraft filter for a small block chevy? lol. One thing I can say about Motorcraft filters is I haven't had to warranty any engines due to one of their filters failing; while I have seen other brands of filters fail and cause catastrophic engine failure. I will continue to use the Motorcraft filters designed by Ford and built by Purolater on my Ford engines. They might not be rated the best but they have done damn well everywhere I have worked since 1969. Just my two cents.

skutsch wrote: you mechanical engineering types understand this stuff so much better

I agree with Joe!! I still feel Fram makes a junk filter!

I find some value in his construction evaluation but the filtration test doesn’t have any real value IMHO. It appears to be only a test of the flattened media at a subjective pressure drop. That doesn’t have much real world correlation to how well the filter would work.   A small amount of highly restrictive media which would score well on this type of test would cause a very large pressure drop across the filter, which aside from placing more strain on the engine would slow down the overall oil flow rate through the engine (by causing the bearing surfaces to see less pressure post filter).    

Additionally to me it seems using a vacuum to pull oil through the paper doesn’t simulate 14 psi of oil pressure but rather 14 psi of pressure drop in the oil filter.. which would be excessive. Most filters would be sending oil unfiltered through their bypass valve back to the engine by that point, 10 to 12 psi used to be a typical bypass pressure rating point back when I paid attention to such things.
So the filtration media might be awesome, but if it restricts flow too much then all the oil is going to bypass it anyway, and if it filters very well but only at pressure drops it will never see then that also doesn’t help things.

I don’t doubt that the high end fram filters are better than they used to be, but I would stick to tests that show pressure drop at reasonable flow rates through the filter assembly.   Preferably at different loading conditions ( Ie how well does it filter after the first 1000 miles, and how much oil pressure does it rob while doing so).

Personally, knowing how many rpms we regularly run our motors, I would say we would be better served by a bunch of relatively porous paper, than by relatively high filtration paper because at 3600 rpm I am guessing too much of the latter would have almost all the oil bypassing the filter element and returning directly to the bearings (particularily with you guys that run that 20-50w stuff).   

Very interesting. It is nice to see critical thinking vs. marketing and personal anecdotal evidence as it relates to these products.

Great information Steve! Thanks for going the extra mile to find it, post it, and further explain it. Its nice to see solid data.

For what its worth, I have had a couple of parts guys and oil change guys tell me Wix is a great filter. It seemed to score pretty high on all the charts. I might have to take a look at using them if they are easy to find.

Ok, so in looking closer at the data, in an attempt to provide some more analysis for DaveG (more on that in a moment Dave), I realized that when I removed the pricing and re-ranked the filters, I only averaged the scores. To be true to the original analysis, I should actually use the weighted analysis as was done in the original evaluation, so you can see the true impact that price has on the ranking. I re-worked that information to come up with the following new ranking based on the weighted average as originally defined by author of this study:

I was never one to buy into the whole Fram bashing thing. I think its all a personal preference. I use both Fram and Motorcraft with no issues.

Question: Fram did both bad and good in the tests. Which Fram filter is the good old beloved "Orange Dome of Death" (as I have seen it referenced on internet blogs). I assume the orange one is the one that scored lower??

Also, judging from the picture above, I didn't know Fram filters had such nice rounded bottoms on them. I do like that grippy stuff they put on them. It would be nice if Motorcraft did that.

Oil filter tests are misleading the problem with frame filters is that when the elements get dirty the collapse or rip and the dirty oil bypass's the element. I have seen this first hand.