Rick's Free Auto Repair Advice

Best Oil filter

Who makes the best oil filter?

There’s no such thing as a single best oil filter brand

All the major oil filter manufacturers make really good oil filters. Wix, Fram, Bosch, Purolator, Mann, ACDelco, Motorcraft, Denso, Mahle, Champion Labs, and Valeo all make oil filter for retail and for carmakers. All the other brands are made by these companies or smaller players.

Most oil filter companies make several grades of filters and several brands

That’s right, many of the different brands you see out there are made by the same company. They’re just private labeled for different auto parts stores so you can’t compare apples to apples.

Don’t judge an oil filter by its advertised dirt holding capacity

Filter media efficiency ratings can be misleading if you don’t understand the terms. Some filter companies advertise their filters by listing its dirt holding capacity. But unless they also list its nominal rating as well as its efficiency, the dirt holding number is meaningless.

A filter that lists a NOMINAL rating must also have an EFFICIENCY rating. So a filter that lists a 30-micron nominal rating with a 20% efficiency is a filter that only filters out 20% of particles 30-microns or larger. In other words, it’s not a very efficient filter because it allows 80% of 30-micron particles to pass through.

However, a filter that has a 30-micron ABSOLUTE rating will filter out 100% of all particles 30-microns and larger.

Filter construction is only relevant up to a point

Lots of time is wasted on oil filter teardown studies that really don’t prove anything about the filter’s ability to remove harmful particles. Here are some examples of bogus filter characteristics

Pleat count is irrelevant

Unless you know the nominal and efficiency rating of the media, the pleat count or total square inches of media doesn’t tell you how good the filter is. A filter with fewer pleats or smaller size, but a higher nominal and efficiency rating can easily out-filter another filter with more pleats and more filter media.

End cap material is irrelevant

People make a HUGE deal about end cap material. It’s a red herring. All end caps, whether metal or resin impregnated cardboard are glued to the pleats. It’s the glue that makes the difference in how well the filter seals against bypass, not the end cap material. In fact, many cartridge filters for Toyota don’t even have end caps any more, and many of the large aftermarket suppliers that do use end caps, have switched away from metal to more “glueable” materials like plastic. If you’re going to use an end cap, the type of glue you use and how it bonds to the end cap is far more important than the end cap material. Bottom line: there’s no scientific study that proves that metal end caps are more effective at preventing bypass than other types of materials.

Anti-drainback valve composition IS important

Economy filters use neoprene for the anti-drainback valve. Neoprene works fine for a while. But as it ages and heats, neoprene becomes stiff and cracks. At that point it allows the oil to drain out of the filter if the filter is mounted sideways or vertically. A silicone anti-drainback valve remains pliable its entire life. So look for a grey, blue or orange anti-drainback valve if you want the best oil filter.

Oil filter history

The first oil filters used steel wool, wire mesh, screens, and felt. The next generation moved on to cotton and other fabrics. Then came disposable filters made from cellulose filter paper. Before synthetic oil and extended oil change intervals came around, manufacturers used only 8 different types of cellulose papers. Then things changed.

Keep that in mind as you review the numerous oil filter reviews and “studies,” because most are woefully outdated. Many of these studies show a pleat count or total square inches of filter media. However, since car makers now rely on almost 80 different types of filtration media, square inches of filter media means nothing unless you know the efficiency of that particular media. In other words, a high-efficiency filter made from synthetic glass and cellulose can actually filter out more and smaller particles than a low-efficiency filter with more square inches of material.

You simply can’t interpolate good test results from a part number to reflect the overall effectiveness of the entire brand. Keep in mind that manufacturers build their filters to match the needs of a particular engine.

Economy, OEM and premium oil filters

A high-quality oil filter is built from quality components. First, it must have a quality filter media. Most economy filters are made with cellulose that’s only about 80% efficient. But a multi-layered premium filter is made with cellulose and synthetic glass fibers that are 99% efficient. That extra filtration traps more harmful particles and sludge. Next, the filter must have enough surface area to keep filtering for the full life of your oil change. Most people think that means a larger size filter or a filter that’s packed with more pleats — not always true!

Again, this comes back to the filter media’s composition and efficiency. Some filters made with synthetic filter media can last far longer than a conventional filter twice the size.

Aside from the filtering media, the differences are in the filter pleat support, bypass valve, anti-drainback valve, and end cap design and construction. Economy filters, (like the one shown below and to the right) have a plastic core cut-away view of an oil filter core support made of plastictube that only partially supports the filter media. In a spin-on filter design, oil enters the pleats from the outside and drains back to the engine through the core tube. In that configuration, you want as much core support as possible to prevent the pleats from collapsing and disintegrating into the core as the filter clogs.

The premium quality filter below and to the left has a metal mesh core support to reinforce every pleat.

image of synthetic glass oil filter media

 

 

 

 

 

 

A bypass valve opens during periods of high pressure. It allows oil to bypass the filter media when the filter has reached its end of life. Once the bypass opens, oil bypasses the filter media and drains down the core tube.

If the bypass valve doesn’t operate properly, the pressure can blow out the O-ring seal and in some extreme cases, destroy the tin can. Some carmakers install a bypass valve in the oil pump, so those filters don’t need the valve. The economy filter shown below skipped the traditional metal spring-loaded bypass valve and relies instead on a combination anti-drainback/bypass valve. The rubber valve collapses during high-pressure cycles. That allows the oil to drain down the center tube as well.

Finally, the filter must have some type of anti-drainback valve to prevent

cut away views of oi filters

dry startups on vehicles where the filter is mounted on the top of the engine, on its side or at an angle. Economy filters use a Nitrile (black rubber) valve that can harden and crack after 3,000 miles. Premium filters use a silicone anti-drainback valve that can last the entire length of an extended oil change (7-10,000 miles). It’s easy to tell the difference between the two materials—nitrile is black. Silicone is either orange or light gray. You won’t find silicone valves on economy filters—the manufacturer just can’t afford to use those costlier materials.

Oil filter dirt holding capacity specs are a red herring—kinda

Engine oil filters must do these three things well:

1) Remove the size of contaminants considered to be most detrimental to that particular engine. This is based on engine material design and clearances, so it’s different for every engine.
2) Have enough contaminant holding capacity to last the recommended oil change interval.
3) Provide contaminant capture yet allow oil flow without increasing pressure beyond carmaker specs, even at cold temps.

Those requirements can create contradictions. For example, a filter that captures smaller particle sizes may also restrict oil flow at cold temps. In addition to restricting oil flow, it may clog faster and go into bypass mode where it stops filtering completely.

Economy versus premium oil filters

Today filter manufacturers use well over 80 different types, and they range from cellulose to synthetic glass, to a combination of both. Cellulose filter media excels at trapping dirt particles. Synthetic media excels at trapping sludge and combustion byproducts. That’s why these filter comparison “studies” are baloney. They simply don’t duplicate real engine conditions. In the latest studies, the authors heat the oil to make it break down. Great. But in order to create sludge, you need more than just heat. You also have to introduce combustion byproducts in real-world amounts and subject your samples to hundreds of heat/cold cycles. Not a single one of these studies does that (that I’ve seen).

So where does that leave you as a buyer? Well, putting no stock in filter studies for one. Next, understand that all filter manufacturers make several different quality levels, so buying by brand alone doesn’t work.

How to buy the best oil filter

If you’re running conventional oil, have under 100,000 miles on the odometer, drive under the car maker’s severe conditions (as defined in the owner’s manual) and you change your oil according to the manufacturer’s recommended intervals (usually 3,000 miles), you can probably get by with an inexpensive filter. It’ll most likely be made with cellulose filter media. It’ll most likely have a nitrile (versus silicone) anti-drainback valve. But those are fine because you’ll be changing your oil according to the recommended schedule. If you don’t change your oil and filter according to the manufacturer’s schedule, you darn well better install a better filter.

If you meet all of the above conditions but have a higher mileage vehicle, move up to a better filter. As engines wear, they produce more blowby and that increases your chances of sludge. A higher-quality filter will do a better job capturing sludge particles.

If you’re running synthetic oil, buy the best oil filter that’s made with synthetic filter media or a combination of synthetic and cellulose.

Oil filter brands

The majority of all retail, wholesale and OEM automotive oil filters are made by just four companies: Bosch, Mann+Hummel, FRAM and Champion Labs,

Purolator Oil Filters

Purolator is owned by Mann+Hummel headquartered in Ludwigsburg, Germany

Bosch Oil Filers

Bosch is owned by Robert Bosch GmbH, headquartered in Stuttgart, Germany. Bosch purchases many of its filtration raw materials from Mann+Hummel.

Fram Oil Filters

As of March 1, 2019, Fram is owned the Trico Group which is now renamed as First Brands LLC

Trico brands are: Trico Wiper Blades, Anco Wiper Blades, Airtex Fuel Pumps, Carter Fuel System Components. Fram Oil and Air Filters, Strongarm Gas Lifts, Autolite Spark Plugs, ASC Cooling System Parts and ASC Water Pumps.

Wix Oil Filters

Wix is owned by Mann+Hummel headquartered in Ludwigsburg, Germany.

Champion Laboratories, Inc.

Owned by First Brands LLC. Champ Labs Manufactures oil filters under private label for auto parts stores, OEMs and under their proprietary brand LuberFiner. UCI also owns Airtex, a manufacturer of fuel pumps.

 

©, 2015 Rick Muscoplat

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Posted on by Rick Muscoplat



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