I got my pair of Filter Magnets installed today.

[CarlB]

In one of his recent Youtube videos, the oil geek suggests this very thing, but using a magnetic oil drain plug, instead of the filter magnets. He implied that it would have value through the first few oil changes, until you observe that the engine wear has significantly reduced and stabilized. His reasoning is the first time that I have found any real value in a magnetic oil drain plug, or filter magnets. I've always considered them a fun experiment, that enhances the entertainment of our oil changes, but unnecessary to protect an engine from premature wear and failure. By premature, I mean that the rest of the car will wear out long before most modern engines.

It's definitely a good visual indicator. The folks that cut open filters will enjoy a magnetic plug.

 

[CarlB]

Here's a few things I know. A NAPA Gold or Microgard Select oil filter made by Premium Guard catches 23-25 microns @ 99%, which means it's not catching all particles smaller than 23-25 microns.

Filtermag catches all sizes of ferrous particles from 2-40 microns that circulate in oil. I think that's a good thing.

Most UOAs only detect particles that are 2-5 microns (if I understand correctly).

How can ferrous particles from 6-22 microns get detected? By getting trapped by magnets and then being seen as grey scum on examination.

So I don't think UOAs tell the full story of how much ferrous material. I think magnets are more effective than some people realize.

More testing is fine for anyone who wants to do it, and Zee0Six outlined a sensible test procedure in post 33 if anyone wants to do it.

I'm already sold and am a believer. If you've never put a Filtermag on an oil filter and later removed it, then you cannot conceive of how strong the magnetic field is. If you get a Filtermag and experience it, then you'll understand.

Also, Filtermag is rated to work from -40F to 300F. So temperature is not a concern.

I bought a pair/set of SS Filtermag. A pair/set of MC Filtermag would have been even better due to 54% more surface area, but I didn't want to spend that much.

It's not just smaller particles. 99% efficiency isn't catching all particles inside 23-25 microns either. 1 in 100 will pass through.

A single advertised rating isn't enough to determine it's efficiency at different micron levels. Without test numbers of the efficiency below 23, we don't know what it is. It could be .01%, 50%, 98.7%, etc. It's probably not 0%, but there isn't information to determine that from "Premium Guard catches 23-25 microns @ 99%."

 

[Carlostrece]

As I stated I own a lot of magnets- very very strong ones. Not hard to conceive. Kind of an odd statement

And for the record I have no doubt magnets catch iron particles

Earlier you mentioned you don't trust weak magnets. I agree.

I just wanted to state that Filtermag are so strong it's difficult for a person (not specifically you, but people in general) to understand the power of these neodynium magnets until they experience them.

Earlier you questioned how hot can they be and still perform. That's why I posted the op temp range of Filtermag is -40F to 300F.

 

[Pablo]

Earlier you mentioned you don't trust weak magnets. I agree.

I just wanted to state that Filtermag are so strong it's difficult for a person (not specifically you, but people in general) to understand the power of these neodynium magnets until they experience them.

I only have one wound from magnets!! Hertz thinking about it!!

I have some I can’t even slide apart

No worries

 

[Carlostrece]

I only have one wound from magnets!! Hertz thinking about it!!

I have some I can’t even slide apart

No worries

Years ago, working on my Jeep Wrangler, my finger was between a Filtermag transmission pan flat magnet and my rear diff housing. It smashed my finger so hard it felt like it'd been hit with a hammer.

 

[ZeeOSix]

A single advertised rating isn't enough to determine it's efficiency at different micron levels. Without test numbers of the efficiency below 23, we don't know what it is. It could be .01%, 50%, 98.7%, etc. It's probably not 0%, but there isn't information to determine that from "Premium Guard catches 23-25 microns @ 99%."

Some filter makers use to give the efficiency at 99% and 50%. Purolator Spec Sheets show that, and Wix use to give those beta ratios. Would be nice if all filters had that info for comparison. Most filters that are 99% @ 20u are still going to be pretty decent at 10u, like around 50-60% efficient. Some like the OG Ultra were even much better than that (80% @ 5u per Motorking at Fram).

 

[Carlostrece]

Some filter makers use to give the efficiency at 99% and 50%. Purolator Spec Sheets show that, and Wix use to give those beta ratios. Would be nice if all filters had that info for comparison. Most filters that are 99% @ 20u are still going to be pretty decent at 10u, like around 50-60% efficient. Some like the OG Ultra were even much better than that (85% @ 5u per Motorking at Fram).

If the filter is made to remove extremely fine particles (like 5-10 u) at what point does flow restriction or clogging become a concern?

Magnetism doesn't restrict flow nor cause clogs.If anything, it makes clogs less likely.

 

[Olds394]

I used to get every car magazine I could find. Saw FilterMag advertised around 2001 and been running them since.
I miss Car Craft the most I think, but canceling Import Tuner was the crime of the century.
If the magnet helps the filter isn’t that good?

 

[CarlB]

If the filter filtrates extremely fine particles, at what point does flow restriction or clogging become a concern? Magnetism doesn't restrict flow.

Filters actually increase efficiency as they get loaded until they are a restriction enough for the bypass valve to open. The point at this happen all depends, but shouldn't happen in normal OCI. Just know it's accumulating from the moment it is installed.

Magnets are not immune to becoming overloaded. If we assume the magnet is doing something that filter cannot, then it will have a linear falloff in ability to capture. As it accumulates ferrous metals, then it will stop being able to capture them effectively. The material collecting will be further and further away until new material just passed by without interruption.

 

[CarlB]

I used to get every car magazine I could find. Saw FilterMag advertised around 2001 and been running them since.
I miss Car Craft the most I think, but canceling Import Tuner was the crime of the century.
If the magnet helps the filter isn’t that good?

It depends. If the magnet were $50 and you save $50 on filters due to running them for longer intervals, then you broke even. Hopefully eventually it starts making your filter costs cheaper. Worse case you buy it for $50 and then keep the same OCI. Now you are spending the same on filters, but also in the red from magnet cost.

Upside, you get to cut the filter open and inspect the visible amount of ferrous metals on the housing. We can't put a fixed price on that, it's all subjective value.

 

[ZeeOSix]

If the filter is made to remove extremely fine particles (like 5-10 u) at what point does flow restriction or clogging become a concern?

Depends on the media design. The OG Ultra was 80% @ 5u (look at Ascent's ISO 4548-12 graph), had pretty low dP vs flow and was rated for up to 20K miles. Some pretty high performance bench marks to beat.

 

[ZeeOSix]

Filters actually increase efficiency as they get loaded until they are a restriction enough for the bypass valve to open.

Not really. Go look at the big Ascent ISO test thread. Every filter he tested lost efficiency as the filter became more loaded. This has been discussed many times. This is one reason that lower efficiency filters really start losing efficiency as they load up. One think people shouldn't do is run a low efficiency filter for long OCIs that would allow it to load up more with debris and start shedding more and more as the OCI goes longer.

Magnets are not immune to becoming overloaded. If we assume the magnet is doing something that filter cannot, then it will have a linear falloff in ability to capture. As it accumulates ferrous metals, then it will stop being able to capture them effectively. The material collecting will be further and further away until new material just passed by without interruption.

That would be an extreme case, and if it did taper off some it's still much better than if there was no magnet at all.

 

[ZeeOSix]

It depends. If the magnet were $50 and you save $50 on filters due to running them for longer intervals, then you broke even. Hopefully eventually it starts making your filter costs cheaper. Worse case you buy it for $50 and then keep the same OCI. Now you are spending the same on filters, but also down in magnet cost.

I don't view using a magnet to catch ferrous debris that the filter can't catch as "saving on oil filters". It's more like saving some added wear on the engine. I'm not going to extend an OCI because I have a magnet in the system.

 

[CarlB]

Not really. Go look at the big Ascent ISO test thread. Every filter he tested lost efficiency as the filter became more loaded. This has been discussed many times. This is one reason that lower efficiency filters really start losing efficiency as they load up. One think people shouldn't do is run a low efficiency filter for long OCIs that would allow it to load up more with debris and start shedding more and more as the OCI goes longer.


That would be an extreme case, and if it did taper off some it's still much better than if there was no magnet at all.

I think you missed the point. It isn't about magnet being good or bad, it's that a magnet is also susceptible to the same unnecessary fear.

 

[ZeeOSix]

I think you missed the point. It isn't about magnet being good or bad, it's that a magnet is also susceptible to the same unnecessary fear.

What unnecessary fear?

 

[CarlB]

I don't view using a magnet to catch ferrous debris that the filter can't catch as "saving on oil filters". It's more like saving some added wear on the engine. I'm not going to extend an OCI because I have a magnet in the system.

We don't have any studies that they are causing meaningful improvements to car engine wear, but we have seen them regarding filter life.

If we want to jump the gun and say that magnets are reducing wear in a meaningful way, then it's a different break even calculation.

 

[CarlB]

What unnecessary fear?

If the filter filtrates extremely fine particles, at what point does flow restriction or clogging become a concern? Magnetism doesn't restrict flow.

Magnetism and Filters are both susceptible, but also no need to worry.

 

[ZeeOSix]

We don't have any studies that they are causing meaningful improvements to car engine wear, but we have seen them regarding filter life. If we want to jump the gun and say that magnets are reducing wear in a meaningful way, then it's a different break even calculation.

I have a real hard time believing using a filter mag or magnetic drain plug is going to "improve an oil filter's life" in any meaningful way on an automobile engine where it would be a clear justification to run the filter longer than specified. I do however think based on pretty much every wear vs oil cleanliness study I've read that removing as much ferrous debris as possible out of the oil will help reduce engine wear over the long run.

 

[Carlostrece]

Filters actually increase efficiency as they get loaded until they are a restriction enough for the bypass valve to open. The point at this happen all depends, but shouldn't happen in normal OCI. Just know it's accumulating from the moment it is installed.

Magnets are not immune to becoming overloaded. If we assume the magnet is doing something that filter cannot, then it will have a linear falloff in ability to capture. As it accumulates ferrous metals, then it will stop being able to capture them effectively. The material collecting will be further and further away until new material just passed by without interruption.

When you say efficiency you're referring to how fine particles it can catch. I was referring to flow restriction. Two different things.

A Filtermag's magnetic field strength is not going to diminish that easily. Have you ever put a Filtermag on a filter and removed it?

 

[CarlB]

When you say efficiency you're referring to how fine particles it can catch. I was referring to flow restriction. Two different things.

A Filtermag's magnetic field strength is not going to diminish that easily. Have you ever put a Filtermag on a filter and removed it?

As the filter loads, it becomes more restrictive.

As the magnet catches, it becomes less effective at capturing. Imagine a drain plug with a magnet, eventually it will be loaded enough it no longer captures new iron flakes or some fall off from the turbulence. "inverse square law" The more distance from the magnet, the less magnetism.