Oil Filter Information

Groan. Read the warning on the website.

If you want to determine the "best" filte, use the SAE tests, not an eyeball evaluation.

Many people ignorantly cite the study to damn the entire Fram line of filters out of hand, yet the author of the study has the Fram Tough Guard in the "Recommended" list. Imagine that.

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

If nothing else, all that pile of information should make you aware that there are really CRAPPY filters out there compared to the better ones! And in my opinion, an SAE approval is the automotive version of a UL listing for home products--someone paid the License Fee.

I highly suggest you spend a little money and chop up a few of your favorite brands and do come comparison. Two things that are difficult to ignore are the Square Inches of filter material and the type of Relief Valve.

Don't just buy a pretty paint job!

Bruce

It's still better than an eyball evaluation, actual filtering ability is more important than looks.

Square inches of material means nothing if the material is less efficient.

Yes, but an eyeball evaluation can reveal weak construction, poor assembly, and lots of other things that would make me avoid a filter. And presumably a smart buyer would ONLY be comparing filters that meet the same approvals and wouldn't even bother with fly-by-nights no matter how "good" they look to the eyeball anyway.

Ah, but here's the rub. An efficient filtration material will have more flow resistance per unit area than a less efficient material. So if you have a MORE efficient material but LESS area, you pay a huge price in backpressure which just means the bypass valve opens sooner. IOW, if you see a filter with far less filtration area than another, odds are it has a far LESS efficient filter material.

So in the final analysis, more area is a good thing, provided that both filters trap the same minimum particle size.

You sure that's how the filtering industry defines "efficiency"?

I don't see that conclusion. If the filter material has more resistance per unit area, it's just as likely, if not more, that they will use more area to give overall better properties (including the ability to hold more total crud before hitting high resistance).

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')

I think we're in violent agreement, Bill. I was pointing out that when you do see a filter with relatively little surface area, it probably has a material that has holes bigger than Kansas so as not to generate back-pressure.

Yep - you're right. I still would like to see what the filter industry uses as a definition of "efficiency".

Bill Putney (To reply by e-mail, replace the last letter of the alphabet in my address with the letter 'x')