How does FilterMag work?

Within the tight clearances of modern engines, normal wear generates tiny steel particles that are carried away in your oil. These particles are so small they pass right through any standard oil filter. When the oil circulates back into the engine these same particles are carried into every lubricated space. This particle-laden oil will continue to lubricate but it will also cause an exponential increase in wear while it circulates. The longer you use the oil, the greater the wear. FilterMag extracts normal, wear causing, steel particles from your oil with its powerful, focused, magnetic field technology.

These particles are permanently trapped on the inside wall of the filter and are thrown away when you change the filter. Slide the FilterMag off the old filter; snap it onto a new one and it goes right back to work protecting your vehicle.

What is the difference between Maximum Protection and Powerful Protection?

Maximum Protection is a pair of FilterMags. Two FilterMags expose almost all of your engine oil flowing through the filter to FilterMag’s powerful focused magnetic field. This provides twice the opportunity for FilterMag to capture wear-causing particles in your oil.

A single FilterMag gives your engine Powerful Protection to remove wear-causing particles at a lower cost.

How do I select the right size FilterMag?

  1. Measure the diameter of your filter, or
  2. Search for your filter’s diameter at any filter manufacturer’s website.


FilterMag SS models come in three sizes ranges (Small, Medium, and Large).
Chrome (MC) or Black (MB) models are available only in Medium.
No matter what the size, pairs cost the same, and singles cost the same.

What is the difference between the TM-360 and the TM-180?

The TM-360 (Maximum Protection) has double the magnetic surface area as the TM-180 (Powerful Protection). Both are designed for installing externally on the outside of automatic transmission fluid pans.

Be very careful with the TM-360 and TM-180. They are extremely powerful. Leave it in the box until you are ready to install. Wear safety glasses when installing any FilterMag, but especially with the TM-Series.

How do I install the GP-101?

The GP-101 is a bare magnet that must be installed internally on the inside of a steel differential or manual transmission housing cover. Be sure to install away from any moving parts.

Be very careful with the GP-101. It is extremely powerful. Leave it in the box until you are ready to install. Wear safety glasses when installing any FilterMag, but especially with the GP-101.

How can particles too small to see hurt anything?

The vast majority of normal engine wear comes from particles of 2-20 microns in size. Steel particles do the most damage when they get trapped between two moving parts. Most of the clearances in a modern engine are between 2 and 20 microns. Most oil filters are only rated to capture particles down to about 20 microns. (A very sharp eye can at best see 40 micron particles.)

I have a problem with my order.

If your FilterMag doesn’t fit, or there are other issues with your order, contact us. We’ll make it right.

Will FilterMag invalidate my car’s warranty?

No. FilterMag’s snap on design is completely non-invasive so it has no effect on the flow of oil in your engine. Furthermore, it’s against US law (Magnuson-Moss Act) to automatically invalidate any warranty due to after-market additions.

My engine has never broken down.

Great! FilterMag will help make sure it doesn’t in the future. How would you feel about your engine lasting a lot longer?

Why can’t I just stick an ordinary magnet to the outside of my oil filter?

While FilterMag is a simple to use solution, it is derived from complex science and advanced engineering. Placing magnets on the outside (or inside) of your filter won’t have nearly the same effect. The FilterMag is a three segment system of which magnets are a key component. The size, shape, and surfaces of our magnets are designed to focus a magnetic field at the proper depth inside your filter. Our patented FluxCon shielding further focuses the magnetic flux into the filter while shielding the engine compartment from ANY magnetism to protect your vehicle electronics. To see more about the anatomy of a FilterMag you can click HERE.

Will a FilterMag lose its magnetic energy at 178°F? My oil runs at that temp all the time.

No. We use robust, temperature compensated magnets rated to 300ºF—well within any normal operating temperature of any engine or drivetrain component. Most ordinary magnets, however, do start losing magnetism around 178 ºF.

Do FilterMags stay in place on their own or do you have a method to attach them?

FilterMags stay in place by their own magnetic strength. Since 1999 we have not had one reported incident of a properly installed FilterMag falling off an oil filter.

For example, we have significant experience with off road racing. Specifically racing such as the Baja 1000 race. Many of these racers run FilterMags as they fly through the air and come crashing down from the jumps for more than 1,000 KM. We have never had a report of a lost FilterMag. Shown below is one of the top off road racers in North America, John Holmes, who runs FilterMags for every race.

If you believe your conditions might be more extreme, there is an additional method that can be used to further secure them. We use this method on aircraft. A vibration resistant stainless steel band clamp can be placed around the FilterMags. Safety wire is used to ensure the filter cannot come loose. The band clamp may also be safety wired for triple protection. CLICK HERE to see an instruction sheet from our AeroMag product that shows a standard installation on an experimental aircraft.



Have you experienced any problems with the extra weight on the filter, as the load on the mounting thread rises and the gasket may get loose leading to oil loss? What is your recommendation for this? Do you have calculations about this influence?

Once again, we have never seen an oil filter come loose while FilterMags were installed. We have never had a report of oil loss caused by FilterMag. Because of this, we have not done any calculations or simulations. Obviously, the moment arm is short and the masses involved are small. When a pair of FilterMags is installed, the additional mass is fairly evenly distributed, so it seems unlikely that high enough rotational forces could be created to loosen the filter.

Next to vibration, the force created by accelerating the mass of the oil contained in the filter is probably the greatest influence on the compression sealing gasket.  Of course, adding a small additional mass to the filter will have some effect, but once again, it seems unlikely to be enough to cause any problems.  If this is a serious concern in an extreme environment, an oil filter can be safety wired after installation to prevent it from loosening under any circumstances.

I already use a premium oil filter. Why bother with FilterMag?

It is always good to use a premium oil filter, but even a premium filter is limited to filtering particles larger than 20-25 microns in size. For an oil filter element to capture smaller particles, it would require a huge increase in overall size to accommodate the restriction to oil flow that would otherwise occur. Normal wear in your engine and drivetrain is driven by particles that are smaller than 20 microns. Eliminate those particles; wear drops dramatically and reliability goes up. FilterMag significantly limits NORMAL wear and tear on your engine and any other protected lubrication systems. How do you feel about your engine lasting 30% to 60% longer?

I have been told that only about 25% of the particles in engine oil are ferrous. The remainder are alloys, copper, brass or aluminum which are non ferrous. FilterMag wouldn’t attract those particles.

The percentage of particles that are ferrous varies widely by type of equipment, operating conditions, maintenance state, and age, but generally speaking the majority of particles found in engine oil are steel. When FilterMags are installed and a used oil analysis is performed by independent laboratories, particle counts routinely drop by 50-82%. Studies show that this equates to a 30-60% increase in lubricated component life.

If the FilterMag removes finer particles and results in cleaner oil, does this actually result in longer component life?

Contemporary data supporting longer lubricated component life by better filtration starts with the landmark study by Sayles and Macpherson in 1982. Their research focused on rolling element bearings, but is applicable to other lubricated components. They showed that wear is directly related to the efficiency of oil filtration. Their idea was that wear is affected by the size of hard particles in the oil. Particles too large to fit between lubricated surfaces would have little effect on wear because they cannot get between two lubricated surfaces. Particles smaller than the minimum thickness of the oil film will also have little effect on wear because they do not come into contact with both surfaces. In their study the particles causing the most wear were in the 3-20 micron size. Their findings showed that removing particles in the oil, down to 3 microns, increased lubricated component life by 600% in rolling element bearings. The now famous “Macpherson Curve” shows this in an excellent graphic format.

Over the following decades many studies demonstrated similar results in multiple lubrication environments. Machinery Lubrication magazine published the results of a meta analysis conducted by Jim Fitch on more than 100 of those studies. The results are now well known in tribology circles as the “Noria Life Extension Tables.” In a nutshell, running cleaner oil does extend the life of equipment. There are four different categories of equipment in these tables. Each category of equipment shows different life extensions depending on improvement in oil cleanliness. Oil cleanliness is defined by ISO 4406 particle counts specifically looking at particles in the 6+ and 14+ micron categories. Generally speaking, life extensions range from a modest 10% for minimally cleaner oil in gearboxes to more than a 60% improvement for a modest cleanup of oil in diesel engines and hydraulics. Experts may sometimes dispute the exact numbers in these charts, but the tribology community fully accepts the concept that removing small hard particles from lubricating oil will extend lubricated component life.

Historically, most engines have run filters in the 25-40 micron range. The rationale is that filtration is needed to remove large particles that could cause significant problems. The limitation is that filtration must allow sufficient oil flow to keep the engine lubricated even after the filter is partially plugged by capturing a large quantity of particles. The smaller the pore size of a filter, the larger the surface area required to provide the necessary oil flow. In recent years, filter element technology has allowed for high efficiency engine oil filters that can filter down to about 15 microns. Currently, to provide full flow filtration below that level would require an enormous filter surface area that is simply not practical for physical and economic reasons. Engines manufacturers accept these filtration limitations and simply consider the wear caused by small particles as “Normal Wear.”

To further examine “Normal Wear,” consider how the Dynamic Clearances of lubricated components in an engine change as they move. When the clearance is open to its maximum, oil flows between the components. The particles that are small enough to be carried into the oil film space between components cause the most wear. When the clearance decreases, the particles are trapped between the moving parts. This process will also create more small steel particles, thus propagating the wear cycle.

FilterMag removes the most common small particles that oil filters cannot: those made of steel. Removing these small steel particles breaks the wear cycle and extends the life of lubricated components.

Will FilterMag work on cartridge style oil filters that fit inside plastic housings?

FilterMags can be band-clamped to the outside of cartridge style filter housings. For more information click HERE.

Many oil pan drain plugs and automatic transmission fluid pans already have magnets.

Many manufacturers do use drain plugs and transmission pans with magnets. These are designed to be visual diagnostic indicators. When your fluids are changed, technicians examine the drain plug and transmission pan for any strange looking debris. These magnets are too small and too weak to be effective as magnetic filtration devices.

What is your warranty and return policy?

We warrant FilterMag consumer products to be free from manufacturing defects for a period of one year from the date of purchase. If you need to return a FilterMag for any reason please contact us in advance for a Return Authorization number. We want you to be happy with your purchase. If you have any problems just let us know so we can help. To see our full warranty please click HERE.