Interchangeable small and large oil filters

[Rooster2]

I have had 98 and 99 Outbacks that used a larger oil filter. Sometime about 15 years ago Subaru went to a smaller oil filter. I realized they were interchangeable, so have begun using the older style larger filter on my newer Subies. I figure that if larger is better, then larger filters better. Has anyone else had this experience of interchangeability?

[1 Lucky Texan]

No experience really. But in the past, I had done some reverse look-ups and saw where our soobs share some filters with quite a few hondas. And, I think I also found where my 2 cars can interchange.

[heartless]

yup, my 2002 Forester calls for one of those smaller mini filters.. found the larger filter that I used to use on the 95 Legacy fits fine, so that is what I use

 

[GeneralDisorder]

There is no significant benefit to a larger filter other than slight (and I do mean SLIGHT) increase in capacity. 

Subaru's tend to shed a lot of metal into the oil. What you want is a *better* filter. And better isn't always bigger - smaller micron rating, and things like the number of pleats in the element (surface area), and the type/location/psi of the bypass valve are much more important than the size. 

And the Subaru blue filters are straight garbage. WIX is good for a cheap filter. If you want the best - Amsoil or Royal Purple (same manufacturer). 

GD

 

[wirelessenabled]

On 3/28/2021 at 9:25 PM, GeneralDisorder said:

There is no significant benefit to a larger filter other than slight (and I do mean SLIGHT) increase in capacity. 

Subaru's tend to shed a lot of metal into the oil. What you want is a *better* filter. And better isn't always bigger - smaller micron rating, and things like the number of pleats in the element (surface area), and the type/location/psi of the bypass valve are much more important than the size. 

And the Subaru blue filters are straight garbage. WIX is good for a cheap filter. If you want the best - Amsoil or Royal Purple (same manufacturer). 

GD

 

Why do you think Subaru blue filters are "garbage"?  I have run them and have over 200K miles on each of the 3 Subarus I do maintenance for.

[idosubaru]

12 hours ago, wirelessenabled said:

Why do you think Subaru blue filters are "garbage"?  I have run them and have over 200K miles on each of the 3 Subarus I do maintenance for.

He’s speaking from data driven, very specific experience, and has researched failure modes rather than asinine regurgitation most people resort too. You can search his past comments on them on this forum. They are very informative if you really want to know. 

“Garbage” is relative. I’ll over simplify. Any average daily driver Subaru will make 200k+ on ANY filter and ANY oil that’s changed often and incurs no major issues. Brand and minor weight variance doesn’t matter. 

your experience with 3 Subarus is a prime example. Correlation doesn’t mean causation.  I’ve maintained dozens of Subarus past 200k and they’ll do fine on the cheapest filter off the shelf.  So that’s all anecdotal. Given that you seem on top of maintenance and incur no extreme use or issues you would have made 200k on those cars with any filter in the store.people do it all the time   It’s the norm. I help people with Subarus and most people do not ever read a car forum or care what brand filter they get.  That’s a lot of people - they routinely make 200k without blinking.

Since that’s true, Subaru filters offer no advantage for that nominal use and you can easily make 200k running them. So does everyone buying the cheapest filter on the shelf. The assumption that Subaru filters are better in this regard doesn’t hold water.  

What happens when oil changes are extended or a vehicle sees above average use (towing, racing, aggressive driving, 400,000 miles, performance, aggressive off-roading, etc), or when complications arise (oil loss, headgaskets, missed or extended oil change intervals, overheating, cylinder misfires, knock sensor failures...etc), can lead to excessive heat and systems degradation in the engine...chiefly oil overheating, localized overheating within the engine, and debris contamination. 

This is when differences in oil and filter matter the most. Not during nominal daily driver use and oil conditions.

Most conversations conflate all those things and ignore those contexts and everyone is right and every is wrong all at the same time. That’s why oil conversations and discussions and opinions are nearly worthless.

Which filters offer better protection under those extenuating circumstances is when the actual data driven differences between them matters.

And Subaru filters do not win the day there.  They will “work” on the most basic level. No one is suggesting they cause issues. But compared to other filters and the outlier circumstances where filters would become an issue...Subarus aren’t a prime choice.
 

 

Edited April 3, 2021 by idosubaru

[Loyale 2.7 Turbo]

If both oil filters are equal in thread, pitch, relief valve pressure and filtering element flow numbers,

Only one thing that went overlooked here, is the fact that the Smaller filter aids to raise the oil pressure faster

and keeps the pressure a little higher on the system, than with a big oil filter.