Bypass Oil Filtration Systems
Reduce Engine Wear with AMSOIL Bypass Filtration Systems
Compared to microscopic dirt particles, your engine is a Goliath, generating intense heat and power as it converts fuel into horsepower. But even a powerful engine is vulnerable to tiny contaminants that can contribute to wear, reduce performance, and shorten engine life over time.
What is Bypass Oil Filtration?
AMSOIL Offers Products To Eliminate Microscopic Engine Dirt
A bypass oil filter system provides an added layer of protection by filtering a small stream of oil at a time, allowing it to capture fine contaminants that standard full-flow filters may miss. Because particles in the 5–25 micron range account for much of engine wear, finer filtration can play an important role in keeping oil cleaner and protecting your engine for the long haul.
Use the guide below to compare system types, then browse the kits that match your engine and service goals.
Why Use a Bypass Oil Filter
The majority of engine wear comes from particles in the 5–25 micron range. An average full-flow filter is typically efficient for particles around 20 microns and larger, which means finer wear-causing material can still circulate through the engine (source: AMSOIL Ea Oil Filters product data bulletin). That’s where an AMSOIL bypass system makes the difference. It continuously filters a portion of the oil and removes contaminants down to 2 microns absolute on first use, which means the filter is rated to capture particles at that size at its published efficiency level, not just reduce them nominally.
Efficient small particle and soot removal
The high-efficiency AMSOIL Ea Bypass Filter element is also an effective soot-removal device. AMSOIL publishes 98.7 percent efficiency down to 2 microns for Ea Bypass Filters. In plain language, nearly all particles at that size are removed as oil passes through the bypass element (source: AMSOIL Ea Bypass Filter product bulletin; ISO 4548-12 efficiency reporting). Some comparisons reference 1 micron filtration, but AMSOIL’s published bypass specification is centered on 2 microns absolute, so that’s the correct number to use when comparing performance.
Equipment constantly runs on clean oil
It’s like giving your engine an oil change every 10 minutes. AMSOIL Ea Bypass Filters typically filter all of the oil in the system several times an hour, so the engine continuously receives analytically clean oil. Cleaner oil reduces friction and heat buildup, increases total filtration capacity, and supports longer component life when the bypass filter is used with a standard full-flow filter.
Increased engine efficiency
Analytically clean engine oil enables engines to run at peak efficiency.
Can significantly extend engine life
The majority of engine wear is caused by particles in the 5-20 micron range. Because AMSOIL Ea Bypass Filters effectively remove contaminants down to 2 microns, your engine receives the ultimate in wear protection. Less engine wear keeps the engine in better physical condition, extending its life.
Increased filtration capacity and life
An additional filter adds additional opportunity to filter particles out of the oil. The full-flow filter removes larger particles down to about 20 microns, while the bypass filter removes the smaller particles down to 2 microns. Working together, these filters provide next-level protection for your engine.
Improved oil cooling
With increased oil capacity, the oil filtration system contains more fluid through which it can disperse heat from the engine. This allows the engine and the oil to run cooler.
Increased fluid system capacity
By installing an additional filter, the engine system has the capacity to hold more oil. The increased AMSOIL fluid capacities and filtration life ensures the equipment constantly runs on highly filtered oil. Engine efficiency is increased, providing extended engine life.
Reduced Maintenance Costs
AMSOIL Bypass Systems provide a dramatic increase in engine protection, helping you avoid costly repairs associated with engine wear.
Dramatically extended drain intervals
Ea Bypass Filters can help users extend their oil drain intervals. AMSOIL recommends using oil analysis when extending oil drain intervals.
What is the proper change interval for Ea® Bypass Filters?
Ea Bypass Filters offer long service life. Do not exceed the limits listed in the chart below.
| EaBP90 | EaBP100 | EaBP110 | EaBP120 | |
| Mileage | 60,000 | 70,000 | 80,000 | 120,000 |
| Hours | 600 | 800 | 1,200 | 1,800 |
| Time | 2 years | 2 years | 2 years | 1 year |
Can oil drains be extended by using a bypass filtration system?
AMSOIL Bypass Filters are designed to filter out fine particles; they are not meant to extend oil change intervals beyond original recommendations. However, when fine particles are filtered out of the motor oil, it may be possible to attain longer drain intervals. This should be determined by used oil analysis. In addition, the use of an AMSOIL bypass system may allow for the use of larger oil filters, which can increase filtering capacity.
Does AMSOIL Synthetic Motor Oil affect new vehicle warranties?
Using AMSOIL synthetic motor oil has no effect on vehicle warranties. A federal law called the Magnuson-Moss Act (1975) prevents original equipment manufacturers from putting conditions on vehicle warranties attached to any product or service identified by brand, trade or corporate name, unless the manufacturer provides that product or service free of charge. This means consumers have the freedom to use aftermarket products of their choice without fear of losing the original limited or implied vehicle warranty. For additional information, contact the AMSOIL Technical Department at (715) 399-TECH (8324) or tech@amsoil.com.
How a Bypass Oil Filter Works
Bypass motor oil filtration features a secondary oil filter with the purpose of eliminating nearly all contaminants from motor oil. An oil bypass filter has high capacity and eliminates much smaller particles than full-flow filters, including soot. Bypass filters reduce engine wear and increase oil volume, but their high efficiencies mean they also have higher restriction and must be used in conjunction with a full-flow filter.
Bypass filters operate by filtering oil on a “partial-flow” basis. They draw approximately 10 percent of the oil pump’s capacity at any one time and trap the extremely small, wear-causing contaminants that full-flow filters can’t remove. Bypass filters have a high pressure differential, causing the oil to flow through them very slowly and allowing for the removal of smaller contaminants. It is called bypass filtration because the oil flows from the bypass filter back to the sump, bypassing the oil flow needed for lubrication. This continual process eventually makes all the oil analytically clean, reduces long-term wear, and can support extended drain decisions when used oil analysis confirms oil condition.
Full Flow Filter vs Bypass Filter
Full-flow filters are more free-flowing than bypass filters, so they are able to support the flow of oil that lubricates the engine. Because they are more free-flowing they are less efficient at removing small particles. AMSOIL Ea® Full-Flow Filters can efficiently remove particles down to 20 microns (source: AMSOIL Ea Oil Filters product data bulletin). You can compare broader filtration options in AMSOIL Synthetic Oil and Air Filtration Products.
Bypass filters only filter a small percentage of the system’s oil at any given time. Denser, more efficient filtration media provides improved small-particle removal. Ea Bypass Filters efficiently remove contaminants (98.7 percent efficiency) down to 2 microns (source: AMSOIL Ea Bypass Filter product bulletin; ISO 4548-12 efficiency reporting).
Used together, full-flow and bypass filters provide comprehensive wear protection against both large and small particles, as well as both short-term and long-term wear. Adding a bypass filter increases total filtration capacity and extends the service life of both filters.
| Filter Type | Particle Size Range | Oil-Flow Role | Restriction | Can Operate Alone? |
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Full-flow filter
|
About 20 microns and larger
|
Handles the engine’s primary oil flow
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Low enough to maintain lubrication flow
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Yes, as the primary factory filter
|
|
Bypass oil filter
|
Down to 2 microns absolute
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Cleans a partial stream of oil for fine contaminant control
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Higher, because the media is denser
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No, it works with a full-flow filter
|
Installation Tips and Common Bypass Filter Mistakes
Mount the filter on a rigid structure close to the engine when possible, and keep it away from exhaust heat, moving parts, and road debris. Plan hose routing before drilling or tightening anything so you have clean pressure and return paths, enough bend radius, and room for service access.
- measure available space before choosing a single-remote or dual-remote layout
- avoid routing hoses near sharp edges, hot exhaust components, or suspension travel
- confirm the pressure source and oil return point before installation
- check whether your vehicle needs a spin-on adapter before ordering a universal kit
- leave enough clearance to remove filters without spilling onto wiring or exhaust parts
Most common mistakes happen before the first fitting is installed: choosing a mount that doesn’t fit the space, ignoring hose clearance, or assuming a bypass filter replaces the full-flow filter. A bypass system works best when the mount location, return location, and service access are planned together.
Single-Remote vs. Dual-Remote Bypass Systems
When you compare single-remote vs dual-remote systems, the main difference is where the full-flow filter stays and how the oil is routed. A single-remote kit adds bypass filtration while the engine keeps its factory full-flow filter in place. The AMSOIL Single Remote Bypass Filter System is the universal example on this page. A dual-remote kit relocates both the full-flow and bypass filters to a remote mount for easier access and installation. The AMSOIL Dual Remote Bypass Oil Filtration System Universal Mount is the universal dual-remote layout.
| System Type | Oil Path | Space Requirements | Included Filters | Service Convenience | Best-Fit Applications |
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Single-remote
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Adds a bypass filter remotely while the factory full-flow filter stays on the engine.
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Needs room for one remote mount and hose routing.
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Varies by kit and fitment.
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One additional filter to change, but the factory full-flow filter may remain in a tighter OE location.
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Limited space, simpler plumbing, and engines that only need added bypass filtration.
|
|
Dual-remote
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Routes oil through a remote full-flow filter and a remote bypass filter.
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Needs more bracket space and more service clearance.
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Varies by kit; some engine-specific kits include initial filters.
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Both filters are grouped together for easier access.
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Pickup diesels, custom installs, and owners who want remote service access.
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Bypass Oil Filtration Systems
Advanced Motor Oil Technology
Upgrade your engine’s oil filtration system with AMSOIL’s Bypass Oil Filtration Systems, featuring advanced technology designed to enhance engine protection. With improved oil cleanliness and reduced wear, trust AMSOIL’s Bypass Oil Filtration System to safeguard your engine and prolong its lifespan, ensuring peak performance mile after mile.
Frequently Asked Questions
A bypass oil filter removes the fine wear-causing particles and soot that a standard full-flow filter may not capture efficiently. It cleans a partial stream of oil at a time, then returns that cleaner oil to the sump so the entire system becomes cleaner over repeated cycles.
No. A bypass oil filter does not replace the full-flow filter. The full-flow filter handles the engine’s primary oil supply with low restriction, while the bypass filter handles finer contaminant removal through a slower, denser filtration path.
Ea Bypass Filters offer long service life. Follow the first limit reached below, and use used oil analysis to guide any drain extension decision.
| Service Interval | EaBP90 | EaBP100 | EaBP110 |
Mileage | 60,000 miles | 70,000 miles | 80,000 miles |
Hours | 600 hours | 800 hours | 1,200 hours |
Time | 2 years | 2 years | 2 years |
AMSOIL Bypass Filters are designed to filter out fine particles; they are not meant to extend oil change intervals beyond original recommendations. When fine particles are filtered out of the motor oil, it may be possible to attain longer drain intervals. This should be determined by used oil analysis. Use oil analysis and sampling tools to monitor soot, viscosity, oxidation, and reserve alkalinity before extending drain intervals.
A single-remote system adds a bypass filter while the factory full-flow filter remains in its original location. A dual-remote system relocates both filters to a remote mount. One of the most common mistakes is choosing a layout before measuring available mounting space, hose clearance, and service access.