samk

Did you ever wonder what the inside of your oil filter looks like?

Check this out


http://minimopar.knizefamily.net/oilfilterstudy.html

Dunasso

I have always used WIX filters and am pleased to discover that they are one of the top filter brands. I am currently in debate over making a switch to synthetic motor and was wondering if I also needed to switch filters. Thanks to the research that you've uncovered I now realize that a change in filters is not neccessary. However, What I have read has lead me to beleive that the best filter is either a WIX or Mobil1. Given the two to choose from, and the fact that I will be changing to a synthetic oil soon (probably Mobil1), I beleive that I will make the switch to the Mobil1 filter aswell, just to keep it all in the family.

Thanks Sam that is one of the most informative threads that has been posted here lately. Good job!

Bill Gregory

FWIW, I recommend only using the Mahle OC54 oil filters. Mahle for years supplied filters for Porsche. The OC54 fits 72-94 911's, and usually run $5-$6 each. The difference is that the Mahle has a relief valve built into it that others don't have. So, while tests of oil filters may look good for the family Ford, I wouldn't use them on any Porsche. If you have the Up-fixin series of books, there have been tests run that articulate the differences in the various filters. Since Porsche started making their filters smaller and in the US, I've exclusively used the Mahle filter.

Dunasso

Bill, I was under the impression that all oil filters have relief valves. Am I wrong? Have I been pressing my luck for the past seven years. The WIX filters that I've been using have been working fine so far. I've always used them (Family thing). Please inform us as to the difference. The last thing I want at this point is more problems, especially when it comes to lubricating the internals of my engine.

Bill Gregory

Per Alan Caldwell of PCA, "The spring loaded pressure relief valve in the original [Porsche] filter surrounds the outlet pipe in the neck of the filter very close to the threaded portion where it attaches to the oil tank and is easily visible. The way it works is that when the filter becomes clogged up and nothing is going through, the pressure becomes very high and cause the valve to open, allowing the oil to flow directly from the holes in the filter base out the center outlet to the tank, bypassing the clogged filter. The aftermarket filter has a relief valve at the other end of the filter which is much cheaper to make and is like the ones used on all other oil filters in the world." Alan defers to the factory filter, partially with the thought that this unique relief valve design has held up for many years from the factory - if there's a problem with the filter, the oil leaves the Porsche oil filter assembly at the base, and doesn't have to flow around the filter to come out the other end on designs with the relief valve at the far end away from the opening. He has also found that other filters don't always have as much filtering material as the OC54, and specifically cites a BOSCH filter as an example. Considering the preceding, when an engine rebuild costs upwards of $10K, why use anything but the factory filter (and the Mahle OC54 was the factory filter until several years ago. Now Purolator makes the Porsche 'made in USA' filter.)

There was a comparison done by some Porsche people, I believe in South Texas, at one point on the web, which was interesting reading, however, I was unable to find it on the web for you.

I believe Rennlist technical advisor Steve Weiner has posted on this topic before....you might want to do a search to see why he recommends the OC54 filter too.