rggpa2

From a recent thread in the A6 forum, the Mahle OC241 filter is known to fit the 2.7L motor as installed in the A6. This looks like the bigger filter for the VW/Audi range of diesel motors. Will this filter fit in an S4, which has a lot less room in the engine compartment? Last time I changed my oil/filter, it seemed like the longer (bigger) Mahle filter wouldn't fit, although I didn't have one to test fit. Has anyone tried this?

MingsS4

why take chances? just use a real audi s4 filter.

rggpa2

I've been using Mann W930/21 filters (in between factory oil changes); Mann is the OE manufacturer for the relabled "real audi s4 filter". In my constant pursuit of "nice" things to do for my car, I've been trying to find out if one of the bigger german OE filters (Mann or Mahle) fit so that I get the greater filtering area of the bigger filter. I'll be the first one to admit that this is probably neurotic; how much additional benefit would I get out of the larger filter area when I change oil @5k and use syn oil (currently Amsoil 0W-30)? But what the hell, if you read this forum, many people obsess about all kinds of things. The only "chance" I see here is buying a filter that doesn't fit. I'm secure that the filtering ability will be greater than the original factory filter. Many A6 2.7L owners use the bigger german filter with no problems.

MingsS4

-Resistance to Flow
-Filterability
-Single Pass Efficiency
-Media Migration
-Collapse
-Inlet and Outlet Anti-Drainback
-Relief Valve

I have read here on AW that the S4 filter has enhanced Anti-Drainback characteristics. Because of this, I just stick with the original Audi part. (and keep my fingers crossed that my turbos don't fail

Ming<ul><li><a href="http://www.sae.org/servlets/productDetail?PROD_TYP=BOOK&PROD_CD=HS-806/95">SAE Oil Filter Test Procedure (Summery)</a></li></ul>

rggpa2

Yipes! I would love to consider all the factors you mention; of course no one has that information for every filter for every application. I've always wondered if the factory expended a large effort to develop detailed specifications for filters and are individual filters from the same OE manufacturer very substantially different from each other (excluding thread type, diameter, gasket location, etc....). Apparently many Audi owners, including I-5 owners, use the diesel filter specifically for the filtering area and the added oil volume. have asked in other forums is anyone had any info regarding actual filtration data along the lines of your list. To no surprise, specific data aren't available to the public.

I agree that you must use a known high quality filter (Mann and Mahle are generally highly regarded and OEM). So far, I've done just as you originally suggested - use the factory filter. Just looking for ways to cure a neurotic techno-itch.