How important is good oil "flow"?

[DrScientist]

I just finished reading the air filter test here on this site. So I had a question. How important is good oil flow? I mean obviously its important. But I am wanting to use one of those new Royal Purple oil filters on my next oil change. They filter very well it would seem. But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.

So that is where I came up with the question. If the Royal Purple brand filter that I am wanting to use filters as well as they say, then surely it must be restrictive. But, is that really all that important? Perhaps even with a restrictive filter, plenty of oil is still getting by. And as such, there is no need for any concern. Or perhaps I should be quite concerned. Which is it?

Oh the car is a 1994 Mustang GT, if that even matters. I'll be running Royal Purple oil before making the switch to Redline. Already bought the RP oil heh.

 

[kemo]

Originally Posted By: DrScientist
I just finished reading the air filter test here on this site. So I had a question. How important is good oil flow? I mean obviously its important. But I am wanting to use one of those new Royal Purple oil filters on my next oil change. They filter very well it would seem. But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.


Amsoil's graphs beg to differ on their old 2 stage filters...

Amsoil also begs to differ on this page that you DO get both... http://www.amsoil.com/storefront/eaa.aspx

quote from the bitog testing...

Quote:
The darker deposits indicate poorer filtration, and lighter ones better filtration. That said, both the cotton gauze type (K&N) and foam filters (Amsoil & Jackson Racing) showed the same levels of filtration. Both performed poorly compared to the fiberous or paper filters (Napa, Baldwin, and Mazda).

 

[PontiacFan]

Originally Posted By: DrScientist
But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.


For an Oil Filter I would probably want good flow, if the Oil Filter is too restrictive it could possibly go into BYPASS MODE, THAT IS IF IT BUILDS UP WITH JUNK. If you have a clean engine, then I would think any oil filter would be fine, if your engine is dirty, then I would just use a cheap oil filter. JMO

 

[DrScientist]

Originally Posted By: kemo
Originally Posted By: DrScientist
I just finished reading the air filter test here on this site. So I had a question. How important is good oil flow? I mean obviously its important. But I am wanting to use one of those new Royal Purple oil filters on my next oil change. They filter very well it would seem. But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.


Amsoil's graphs beg to differ on their old 2 stage filters...

Amsoil also begs to differ on this page that you DO get both... http://www.amsoil.com/storefront/eaa.aspx


I'm... sure they do. Unfortunately, anything they say is nullified by the fact that they're selling something.

 

[JOD]

Originally Posted By: DrScientist
But I am wanting to use one of those new Royal Purple oil filters on my next oil change. They filter very well it would seem. But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.



That's only true if you're using the exact same quality of media. A finer media can allow for both increased flow and better filtration.

I e-mailed RP and asked them for a PSID curve on the 820 filter, and it has excellent flow--better than all but a few filters.

 

[JOD]

Originally Posted By: DrScientist

I'm... sure they do. Unfortunately, anything they say is nullified by the fact that they're selling something.


'nullified'? I'm not sure I'd go that far. I'm always skeptical of manufacturer's claims, but SAE tests are standardized, so faking that data would be pretty unlikely, given the consequences.

The 'marketing' seems to come in to play in how the data are expressed, such as seen in that graph...

 

[DrScientist]

Well in the review here he said it flowed only "marginally" better than paper. So his findings would seem to contradict them.

 

[DrScientist]

Originally Posted By: JOD
Originally Posted By: DrScientist
But I am wanting to use one of those new Royal Purple oil filters on my next oil change. They filter very well it would seem. But, as stated in the airflow test, you can either get good filtration, or good flow. Not both.



That's only true if you're using the exact same quality of media. A finer media can allow for both increased flow and better filtration.

I e-mailed RP and asked them for a PSID curve on the 820 filter, and it has excellent flow--better than all but a few filters.


Better than Motorcraft?

 

[JOD]

Originally Posted By: DrScientist


Better than Motorcraft?


Yes, better than Motorcaft. Using test SAE HS806-2001, at 12 gpm of flow the Ford Racing filter (which flows much better than the regular Motorcraft filter) has 4.2 psid of restriction; the RP filter using the same testing protocol has 2 psid of restriction (this is based on data supplied by the manufacturers in both cases). That's actually the best flowing filter for which I've actually seen data. So, bottom line is that you certainly don't need to worry about flow with that filter.

 

[boxcartommie22]

my stainless steel psid is 1..flows 57gpm and filters 35u absolute no paper filter is able to do this...i am very pleased with these filters!!

 

[boxcartommie22]

ford racing filters:2.5 psid @ 3 gpm,5.6 psid @10 gpm,7.3 psid @13 gpm....i got these figures from ford racing..hope this helps
incidently, our founder bob, preferred good flow over filtration..if i recall

 

[DrScientist]

Hmm... so it could be that the Royal Purple filter is the best of both worlds? The best filtering, and the best flowing?

 

[Steve S]

The R.P. filters are pretty much the same element type as Amsoil and Donaldsons and Fleetguard. Those filters are state of the art for oil filters. The oil filters flow really doesn't matter in a passenger car motor. Oil filters are really unimportant just so there is one and it doesn't fail.

 

[OldCowboy]

Originally Posted By: boxcartommie22
my stainless steel psid is 1..flows 57gpm and filters 35u absolute no paper filter is able to do this...i am very pleased with these filters!!


The bottom line is that your 35u filter lets through all of the particles smaller than 35u. These are precisely those which are responsible for the most wear. You might as well not use a filter.

 

[boxcartommie22]

and your paper filter let through 60-200u of particles also which companies will no tell you.especially when you push your engine then all your oil bypasses the whole thing...the 35u is absolute..15u nominal all single pass.....we can go on all day...

 

[JOD]

do you have one of those Pure Power filters? They look interesting...and expensive. If I knew it would fit whatever my next car would be, I'd consider it.

 

[DrScientist]

Someone said oil filters don't matter? That's crazy talk. Surely you need an oil filter...

 

[A_Harman]

Synthetic media oil filters all the way....

They offer the best of both worlds; finer filtration and lower pressure drop for a given flow. The synthetic media can do this by the benefit of having "depth". Multiple layers catch finer particles, yet give the media 3-dimensional structure to flow more fluid.

 

[OldCowboy]

Originally Posted By: boxcartommie22
and your paper filter let through 60-200u of particles also which companies will no tell you.especially when you push your engine then all your oil bypasses the whole thing...the 35u is absolute..15u nominal all single pass.....we can go on all day...


You drank the kool-aid.

 

[boxcartommie22]

jod, many of the car clubs used these filters here....i use k&p engineering filters..i have 7,880 miles on this oil change..the filter keeps the oil slightly dark amber..oil still has that nice slippery feeling and not gritty like a paper filter makes your oil feel after driving awhile iam going to get a used oil analysis done will post it on here use triton labs here in denver....just my observation and many years with these filters..my 98 vic had 420,000 miles and still going strong when sold the car. used stainless filters 300,000 of that....