Oil Filter Comparison/Evaluation

Ok, in an effort to further the debate on Oil Filters, I have located an updated study and tear down analysis on Oil Filters. I will post the links and results below. But first the caveats:

1.) The study was completed in January 2011, so even this study is over 2 years old, but much more current then the one I have previously referenced. Realizing that manufactures change their products (for better or worse), products referenced here may have changed and could provide different results.

2.) I believe the study to be an improvement over previously referenced studies because in addition to the tear down analysis, it also completed a particulate filtration analysis.

3.) The application was completed using a methodology to simulate a 1/2 ton pick up using an L31 5.7L Gen1e Vortec engine. Obviously this is not a marine application. While the 5.7L chevy block is used in some marine application, it is not the same. For most of the folks on this site the 5.8L Ford block is probably more common. Having said all this the spirit of the analysis is still somewhat applicable to our marine application.

4.) Much of the study is subjective, where empirical analysis is not provided, there is generally documentation of what the subjective analysis was based on, and in many cases photographs of the information.

Link to the Oil Filter Analysis

For those wishing for the Cliff Notes Version
Top 5 (overall):
Fram Extended Guard
Mobil 1
Royal Purple
Amsoil
K&N

Top 5 (elimiating price as a factor)
Mobil 1
K&N
Fram Extended Guard
Wix
Purolator Pure-One

Bottom 5 (overall):
Fram High Mileage
Proline
STP
AC Delco
Shell

Bottom 5 (elimiating price as a factor):
Full
Motorcraft
Pronto
Proline
Shell

More information to follow, let the debate begin...

Here is a summary recalculated removing the Price component:

'crickets chirping'. i wonder how crow is best served?

good stuff steve. interesting to see just how crappy motorcraft stacked up.

Josh, was not my intent, but admittedly I would have to be near the start of that serving line - as I too had climbed on the Fram basher bandwagon, I would say they only have ONE filter at the top of the list and most of their filters are indeed at the bottom. in general I was surprised by a lot of the results, and it does go to show that companies can and do make changes to their products and that you do need to be constantly open to updating your information/opinions.

Really anxious to see what Waterdog has to say. Andy is actually in the industry (oil analysis) and I would consider him an expert on the whole Oil discussion.

Regardless, I think this is a good update to the previous findings.

All I know is if its 80 degrees and I am out on Green Lake for the re-union I would not care if I had a soup can full of Charmin screwed onto the block filtering my oil, I am not turning back to change it. I think I put a wix on last fall. That is the only time I think about the filter.

Wow, I took the time to read the tester's setup and tools used to test and I'd say it was a pretty comprehensive test and it obviously yielded some pretty interesting results. Still want to hear what the naysayers chime in with. I haven't used a Fram filter since I joined on here, maybe that will change, but maybe not. I'm a creature of habit and like to stick with the plan. FL1A hasn't let me down yet....

I have to wonder why the NAPA Gold and the WIX scored differently???They are the same filter!!!

steve is correct, I'm aware of only 4-5 major mfg. of oil filters. Champion being one of the largest. I believe this is the old outdated version you were referencing Old Test

Since then a few of the brands have switched mfgs, but it gives you a good idea of the differences you'll see even from the same mfg. Kinda like batteries. 99% of the time it isn't the mfg that determines the quality(or lack there of) but the spec and budget they are given by the brand. largely the budget, which determines filter material, check valve material, etc.

The reason everyone gets their turn in the barrel is because it seems like they take turns cheaping out on their filters. They build up the reputation, then cut costs and ride the profit train as long as possible. Then repeat when it starts going down hill. The only brands I've seen consistently maintain quality is Mobil, K&N, and for the past 6 years WIX gold. Motorcraft and Mopar both switched suppliers in recent years so I'm curious how their quality will pan out.

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.

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.

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:

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.

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

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).   

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

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