H6 Oil Filter on 2.5L Engine?

Question

I was just reading an article on  advising against substitutingthe 4-cyl. oil filter on 6-cyl engines.Quote:Both filters have the same physical dimensions as far as threads, O-ring,and bypass valve opening pressure (23 p.s.i.) are concerned. However, theH-4 filter has 141 square inches of filtration surface, while the H-6 filterhas 201 square inches of filtration surface.The H-4 filter should not be used on the H-6 engine. Using the H-4 filtermay cause it to become contaminated faster and allow the bypass valve toopen, allowing unfiltered oil to circulate through the engine.unquoteSo would it be a good idea to use the H6 filter on my H4 motor? Would oilflow be improved or time between changes?

y_p_w · Accepted Answer

I think this is the article you mentioned:

If they recommend it, go for it. It's only marginally more expensive at 1stSubaruParts.com ($5.03 vs $4.75). I'm using the 15208AA080 (superceded by the new 15208AA100 part #) filter for the turbo models. I'm not sure about filtering area, but I'm not concerned given that Subaru believes this is the best filter for my application.

I looked at other online parts sources, and subaruparts.com doesn't carry the 15208AA031/S0A5165109 filter, and recommends a single filter (likely 15208AA060) for all the recent non-turbo models.

MN · Answer

I think it may be a good idea to use the H6 filter on an older higher milage looser H4 motor where blowby may contaminate the oil faster much faster.

On a new, fairly new engine I think its not necessary and probably not much helpful if you change oil regularly.

MN

BobN · Answer

That's a good thought.  And since my 98OBW has 221K miles and I've noticedthat the oil does get dirty quite fast, I'll give it a try.  In fact, I'mdue to change the oil this weekend.

H6 Oil Filter on 2.5L Engine?

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