H6 Oil Filter on 2.5L Engine?

[BobN]

I was just reading an article on endwrench.com advising against substituting
the 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, the
H-4 filter has 141 square inches of filtration surface, while the H-6 filter
has 201 square inches of filtration surface.

The H-4 filter should not be used on the H-6 engine. Using the H-4 filter
may cause it to become contaminated faster and allow the bypass valve to
open, allowing unfiltered oil to circulate through the engine.

unquote

So would it be a good idea to use the H6 filter on my H4 motor? Would oil
flow be improved or time between changes?

 

[y_p_w]

I was just reading an article on endwrench.com advising against substituting
the 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, the
H-4 filter has 141 square inches of filtration surface, while the H-6 filter
has 201 square inches of filtration surface.

The H-4 filter should not be used on the H-6 engine. Using the H-4 filter
may cause it to become contaminated faster and allow the bypass valve to
open, allowing unfiltered oil to circulate through the engine.

unquote

So would it be a good idea to use the H6 filter on my H4 motor? Would oil
flow be improved or time between changes?

I think this is the article you mentioned:

<http://endwrench.com/images/pdfs/OilFilters.pdf>

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(superceded by the new 15208AA100 part #) filter for the turbo models.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]

I was just reading an article on endwrench.com advising against
substituting
the 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, the
H-4 filter has 141 square inches of filtration surface, while the H-6
filter
has 201 square inches of filtration surface.

The H-4 filter should not be used on the H-6 engine. Using the H-4 filter
may cause it to become contaminated faster and allow the bypass valve to
open, allowing unfiltered oil to circulate through the engine.

unquote

So would it be a good idea to use the H6 filter on my H4 motor? Would oil
flow be improved or time between changes?

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]

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.

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