Two Oil Filters in One Oil Run

[proffittmarke]

I used to work in the automotive parts manufacturing sector before retiring. This included several years in an engineering specifications testing laboratory. We used to entertain ourselves at work by debating hypothetical scenarios. In my early years, I worked in a laboratory at a major oil refinery.

I have one for my buddies here. It’s actually a potential real-life upcoming scenario for me.

Let’s say I buy a high-end oil i.e. Amsoil SS, Ravenol, MPT, etc. (or Redline in my case) and I plan to run it for a full 15,000 miles, changing the oil filter halfway at 7,500 miles. In my stash, I have an OEM oil filter, about 98% efficiency at 30 microns. I also have a high-end oil filter with 99% efficiency at 20 microns. I want to use both these filters during my 15,000 run, which will take me 6 months. I do 75% highway / 25% city on a ‘22 Sierra with almost 150,000 miles. It runs in 8-cyl. always with a Range Technology module. It has a cold air intake. The truck is serviced at 2X severe service schedule with only the best, by myself, and driven like a grandpa, which I am.

QUESTION: If this was what you had to work with, what order would you install the oil filters?

OEM oil filter at oil change, then high-end oil filter installed at 7,500 miles?

-or-

High-end oil filter at oil change, then OEM oil filter installed at 7,500 miles?

Whatever the consensus here is will dictate what I actually do. If finances allow, I will get an oil analysis report when I change my oil in 15,000 miles. Then, I will do the same scenario for the next 15,000 miles, but switch up the oil filter order and get another oil analysis at the end of the second 15,000 run.

 

[BobsArmory]

For running extended drains the first thing I would do is get rid of that sketchy aftermarket air cleaner and put the factory one back in so you ingest less dirt. Just my opinion.

 

[ZeeOSix]

QUESTION: If this was what you had to work with, what order would you install the oil filters?

OEM oil filter at oil change, then high-end oil filter installed at 7,500 miles?

-or-

High-end oil filter at oil change, then OEM oil filter installed at 7,500 miles?

Whatever the consensus here is will dictate what I actually do. If finances allow, I will get an oil analysis report when I change my oil in 15,000 miles. Then, I will do the same scenario for the next 15,000 miles, but switch up the oil filter order and get another oil analysis at the end of the second 15,000 run.

Nice looking truck! ... and sounds like you take good care of it.

As far as what order to run the oil filters, it shouldn't really matter in terms of wear effect because each filter run will result in some basic stable oil cleanness level based on the filtering performance of each filter. However, if you're going to get an ISO particle count with the UOA at the 15K OCI, then the more efficient filter should clean up the oil to a better particle count than running the lower efficiency filter last. Just doing a normal wear metals UOA isn't going to show much as it doesn't measure total particles of debris in the oil. And a normal Blackstone type of UOA only looks at wear metals that are 5u and smaller, and are pretty insensitive to any wear going on that may be beyond the "benign" realm.

A filter that's 98% efficiency at 30 microns isn't really low efficiency ... it's basically in the middle of the typical oil filter efficiency range of 99% @ 45u to 99%+ @ 20u. So even a particle count may not show a lot of difference in the PC between 98% @ 30u and 99% @ 20u, but should show some difference. Now if you were running a 99% @ 45u vs a 99%+ @ 20u filter then you should see a pretty big difference in the PC, like shown below.

 

[fantastic]

I just need to ask you a question to make sure I understand what you want to do. Are you intending to use the oil for 15,000 miles?

EDIT: I just read the title & seems like you want to run the oil that far. The more efficient filter should be used for the last 7,500 miles.

 

[ZeeOSix]

For running extended drains the first thing I would do is get rid of that sketchy aftermarket air cleaner and put the factory one back in so you ingest less dirt. Just my opinion.

A comment on this ... if an air filter lets dust into the engine, some of that dust will end up in the oil through piston ring blow-by. If the level of silicon from dirt levels are raised due to lower air filtration, it's possible there would be a slight up tick in wear metals if the oil filter is lower efficiency. The oil filter is the only thing left to remove debris that gets into the oil, even if it comes from dirt being blown past the rings and into the oil.

 

[tratman2000]

id just run either filter to 15k as the oil i see no reason to swap at halfway mark

 

[mitsuman47]

Another vote for removing what looks to be a K&N filter, and going back to the paper media that came on the truck. That’ll do more good for your engine than whatever order you decide to run those oil filters.