Along with the Oil Analysis Series I thought it would be good to do a series on oil filters. There are some things you definately should know in this area.
Oil Filters. Orange ones, Green Ones, Blue ones, oh my
Walk into any auto parts store or automotive section of discount store and you are faced with a miriad of choices in oil filters. They all seemingly claim to be the best and to choose any other means certain death for your engine.
If you want 'adequate' filtration for your engine then you certainly could choose just about any of them and do well. But what if you go in with the intention of getting the best filter. How do you quantify such a thing. What standards should you use? If you buy the more expensive filter are you getting the best?
When performing maintenance on your car, particularly lubrication maintenance such as an oil change you have but a few options. You can do it yourself and choose the filter and oil combination you 'feel' is the best. You can take it to someone and 'trust' that their combination is the best. Or you can get a little educated and 'know' which is best.
Im an Amsoil dealer so most make the immediate assumption I am biased. For the most part, they are correct. However, I am not biased because I sell thier products. I am biased because I chose to get informed and when the dust settled Amsoil won out for me. But for most, taking the time to study something like oil filters would take a distant second place to going to the dentist for a root canal.
But wait you say, the filter makers supply us with information so that we can make a good deciscion. Do they? Or are they providing you with just enough information?
What do all those numbers mean
Pick up just about any filter and you are likely to see references to single pass efficiency, multi-pass effieciency, microns, percentages and more. What does all that mean? Unfortunately not a lot. The reason for this is that the provide you with little information concerning how they obtained those numbers.
For instance, if you go to Frams website and look at their information on their Extra Guard Oil filter and you will see that they list a 96% Single Pass effieciency and 94% Multi-Pass Efficiency.
Okay, now what? What exactly does that mean? Those are pretty high percentages, it should be a good filter, right? If they told you the whole story, perhaps. However, they are leaving out crucial information that tells the whole story.
There are standards in testing in which oil filters are evaluated. There is the SAE (Society of Automotive Engineers), ISO (International Standards Orginization) and NFPA (National Fluid Power Association). Of these Ive only seen filter testing from SAE and ISO. If there are oil filters out there that have had standardized testing performed on them from NFPA I have yet to run across them.
In SAE the standard test is HS806 (unless it has changed recently). The ISO test is 4548-12. Pretty much any filter that makes any claims to its performance has used one of these tests. What they don't tell you, though, is where they make it appear they have the best available.
What do those numbers mean: Single Pass Efficiency
In the example of the Fram filter that boasts a 96% Single Pass Efficiency, to be honest, I dont doubt that number. It, in fact, is probably very true. However, there is more to the story here.
The single pass test, as its name infers, is a test in which a filter gets only one chance to filter out debris. How the test is run is that a certain amount of contaminant that has a certain weight is introduced to the oil, allowed to pass through the filter and then what remains of the contaminants is weighed. Since it is known how much the contaminant weighed both before and after the filter a evaluation can be made as to the filters single pass contaminant efficiency. In other words, how much it will stop with one pass through the filter.
Now, that may all seem well and good but here is the sticking point with this test. When it is done they use particles that range in size. The test uses particles that are believed to cause most engine wear, 10 – 20 microns. I disagree with this number a little but lets roll with it for now. Obviously the smaller the particle a filter can stop, the better, all other considerations aside for the moment. With the single pass test, however, how can you derive at which size particles the filter works best? You cant. When you read a single pass efficiency test, you are basically being told that that filter is that efficient at removing particles in that range. Whether it is more efficient at the 10 micron level or 20 micron level you have no way to tell. Notice, however, they don't tell you that on the box. You look and see a number like 96% or 98% and you think WOW this filter must be good. Well it is, on the surface, if you don't know the rest of the story being told.
What do those numbers mean: Multi-Pass Efficiency
The Multi-Pass test is a more recent addition to the filter testing regiment. It differs in a couple of significant ways. First, as its name implies, its a multi-pass test. Meaning the filter gets more than one shot at removing the contaminants. Secondly, the particles that are injected into the oil to be filtered are actually counted rather than weighing them. Its a better test in that you get a truer reading of the filters efficiency. Its also a great test in that it, in my opinion anyway, is more realistic of actual driving conditions. You don't allow your engine oil to just pass through the filter once and then remove it, rather the oil circulates hundreds even thousands of times during the time it is in your motor. So in that regards I think the multi-pass test is a more 'realistic' test. Of course opinions will differ on that, take it for what its worth.
Multi-Pass testing allows more precise testing for particular particle sizes over the life of the filter. Here again though you will see many filter makers just put the percentage on the box and do not tell you what particle size. Well I could tell you that my filter has a multi-pass efficiency of 99% but what would that mean to you if you don't know at what size I achieve that mark. I would say a lot of filters on the market today could easily be 99% efficient at 50 microns, but thats not good for you. If most engine wear occurs between 5 – 20 microns or 10 – 20 micros as the testing assumes, then a 99% efficient filter at 50 micros is pretty poor. Though if I were to just put that percentage on the box with no size indication it would look like my filter was superior to any other.
Absolute Efficiency
One indication of a filters ability is its 'absolute efficiency' rating. Though, unfortunately, most filters do not include this information. You cannot compare a single pass test rating to a multi-pass test rating, its an apples to oranges comparison. You can compare single pass to single pass and multi-pass to multi-pass as long as you take the above information into consideration, that is to say, you know at what particle size they achieve those numbers.
Absolute efficiency is almost and I stress almost the tell tale sign of a filters capability and here's why. If, and it would be a pretty huge if, the absolute efficiency rating is included on the box or filter information, then they are going to tell you the absolutely smallest particle that filter achieves that rating. In other words, a filter maker isnt going to tell you their filter is achieves absolute efficiency at 30 microns when in fact it can do it at 20 microns as well. No, they will tell you the smallest particle they can filter and still achieve absolute efficiency. If all filter makers were required to include this information I think we would see one of two things on the market today. Either a lot of filters would disappear off the shelves because people would only buy the filters that could achieve absolute efficiency at very small particle sizes or we would see a complete overhaul of the filters being produced today.
For definition, a filter is considered to achieve absolute filtration efficiency at a certain micron level if it can remove 98.7% of particles that size. So, if a filter can remove 98.7% of particles 20 microns or larger, it achieves absolute efficiency at that micron level. Its sad that more filters don't include this information simply because it would allow the consumer to make a really good informed decision about filter choices.
Why not make a filter that can just stop all the contamination
Aside from the obvious that if this were done that motors would last much longer than I suspect the auto manufacturers would like there are technical reasons. A chain link fence will stop 1 micron particles, but it wouldn't do so very efficiently at all. However, it would flow a great deal of oil. Therein lies the trade off. You could make a filter that would stop virtually all contamination, but you would do so at the expense of oil flow. High oil flow usually comes at the expense of good oil filtration. Good oil filtration usually comes at the expense of oil flow, to say nothing of the cost. So an attempt is made and balancing good filtration with the necessary oil flow and cost.
There are other options available to aid in reducing contamination such as by-pass filters. Most consumers, however, are unaware of these options and then when they do become aware of them are often put off by the expense. Though in relative terms by-pass filtration is really inexpensive. Compare the cost of, for example, Amsoil's by-pass filtration systems to that of replacing an engine and you quickly see that though the initial cost may be more than one is 'used' to but its value over the long haul is more than the cost of the system.
By-pass filter systems (I'm referencing Amsoil's since that is what I am familiar with) add more oil to your capacity. This is especially crucial in today's engines that are using smaller sump capacities and smaller filters. Just to give you an example, I recently set up a customer with Amsoil on a Nissan Titan with the V8 motor. It barely held 5qts of oil and had a filter that wasn't half the size of a pop can. Amsoil's by-pass filters add from 1.5 – 2.0 quarts of oil using the standard filters up to about 4qts using the larger filters. That extra oil helps to extend the life of the oil since there is more of it to aid in the neutralization of contaminants as well as it adds additional oil for engine cooling to say nothing of the by-pass filters ability to filter contaminants well below that of a full flow filter. Amsoil's new EaBP by-pass filters are achieve absolute efficiency at 2 microns. WELL below where most engine wear occurs.
Conclusions
You should be able to see now that when you pick up a filter in the store you are most likely not being told the whole story. So what are you to do? There are a couple of different ways to go. First you could use a filter that does give you the complete story such as Amsoil which prints their efficiency and micron level right on the filter. Though I think you may be hard pressed to find anyone else doing so. Secondly you could use oil analysis that includes a particle count. Particle counts are going to tell you what contaminants are in your oil currently and at what size they are. This can be a costly matter if you are searching for a filter as every time you try a new filter you are going to have to run a new test. Thirdly, you could use by-pass filtration whether it be Amsoil's or another vendors. Cost is an issue up front for some but it pales in comparison to what an engine or vehicle replacement would cost. I would even go as far as to say its cheap in comparison.
There are other considerations in oil filters as well other than just their ability to trap contaminants. You obviously want one that is well constructed. What good is a great filter that bursts open on you because it couldnt handle the oil pressure. As well, you want a filter that has good capacity to hold dirt. Again, if you have to change your filter frequently because it 'loads' up quickly then it becomes a less useful filter. Incidentally, you wanna know how you can tell if your filter is 'loaded' up and has went into by-pass mode?
You can determine if your oil is bypassing your oil filter by touching your filter after at least 45 minutes to an hour's worth of driving. If the filter is hot, you're probably in good shape. If it's not, the oil is likely bypassing the filter, and it is time for a change.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
Wow that was very informative! I was pretty oil-dumb to start with, but those points all made a lot of sense... food for thought now I suppose.
One question, "You can determine if your oil is bypassing your oil filter by touching your filter after at least 45 minutes to an hour's worth of driving. If the filter is hot, you're probably in good shape. If it's not, the oil is likely bypassing the filter, and it is time for a change."
~Does this go for normal filter setups, or only if you have a bypass filter installed? It seems like a nifty trick to have up one's sleeve, although I'm not really in the habit of running my filter ragged either...
That trick would be true for both, either normal filters or by-pass filters. As a benefit of using Amsoil's dual remote by-pass filter set up, my oil filters are up in front of the car between the radiator and front bumper. So I can lift the hood and reach down and check my filters. So Ive gotten in the habit of checking them every so often to make sure they are both gettting hot.
The full flow filter (your normal filter you replace at oil changes) is going to start getting warm pretty quickly, maybe 5 minutes or so and after a good 30 minute drive you'll know with certainty. My by-pass filter, however, does take about 30 - 45 of driving for it to get as warm as the full flow simply because it does not see the volume of oil that the full flow does.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
I might add though, unless you have the 2.3L duratec motor, reaching down to check the warmth of the oil filter on a Focus is going to be something of a challenge.
That said, its probably a good practice to try and check the filter on a regular basis simply because filters aren't perfect and problems can occur even on new filters.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
Not a problem. I hope to post more articles as time allows. Im close to deploying my new website so Im splitting time between that, family, business and articles. Though the articles, in all likelyhood, will be put up on the business site as well.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
I thought I would add, for those interested, particularly other Amsoil dealers on here, if you look at the new EaO line of filters, it will state I believe on the filter iteself or on the box that it filters 15 microns at 98.7% which is absolute effeciency (hence the name of the filter). On the Donaldson filters they take it a step further. They put it on the filter that it filters 15 microns at 98.7% effeciency and 7 microns at 50% effeciency.
Now, remember the lesson that to give you just one figure or the other is pretty useless. I can say all day long that a filter can filter at 98.7% effeciency but at what size particles? Likewise I can say my filter can filter at 5 microns but at what effeciency?
Amsoil and Donaldson are the one of only a couple makers that I have seen thus far that list both pieces of information so you get an apples to apples comparison. Donaldson goes even further listing an additional rating of 7 microns at 50%. Now, I dont know about you, but a company that lists a particle filtration that is less than absolute speaks of their openess with their data. Furthermore, for a full flow filter to filter at 7 microns with a 50% effeciency is pretty darn good.
Now, lets take a few examples to show you what I mean.
First, Amsoils biggest competitor, Mobil 1:
ExxonMobil does offer a very high-quality oil filter that can be used with any motor oil, but it is an especially appropriate companion to Mobil 1. Mobil 1 Extended Performance Oil Filters contain synthetic fibers instead of the typical cellulose filter media. With a 99.2 percent efficiency rating (under SAE J1858 Multi-Pass Efficiency Test), the Mobil 1 filter is much more efficient than a typical oil filter, removing more particles per pass through the filter. In addition, the synthetic fibers in the Mobil 1 filter have less resistance to oil flow, reducing the potential for the filter to restrict the flow of oil to your engine.
It should be noted the above is taken from their newer EP filter line up.
Well, what do you know. A seemingly very high efficiency, but notice no particle size associated with that rating. It could be 50 microns, it could be 5, we have no way to tell. Now, having said that, given the media they are using I will say it will be around 20 microns. You'd have to call them and hope they would tell you at what size the efficiency rating was determined at. The fact the tout the efficiency and not the particle size leaves me wondering and unable as a consumer to make an informed decision, not so with Amsoil or Donaldson.
Fram:
We took America's favorite oil filter one step further. We added our SureGRIP® feature to assist with installation - no matter how oily things get, the filter stays in your hand. FRAM® Extra Guard® filter media makes the difference maintaining a market leading level of single pass efficiency of 96%.
Their single pass efficiency doesnt even reach the absolute rating, their multi-pass rating is even lower at 94%.
Again, notice no particle sizes with the ratings. They tout the numbers because they are high, and to an uninformed customer as to what it all means, appears impressive. The red flag here, for me at least, is that neither rating acheives absolute efficiency rating, furthermore, no particle size given and knowing its a paper filter I would speculate that the particle sizes are going to be in the 30 micron range, maybe a little less.
Next, Purolator:
Purolator makes a couple levels of filters. Their Purolator Premium Plus and their Pure One line.
I couldnt cut and paste some of the info from their site, so I'll have to summarize.
First their Premium Plus filter.
PremiumPLUS Filtering Media removes 10-20 micron-sized particles under actual driving conditions.
Does that size range look familiar. If not look at the lesson again. Its a single pass efficiency test. In other words, the filter is 'capable' of filtering particles in that range. We dont know whether it is better at 20 microns or 10 microns because no percentage is given. We also dont know how collectively well it does in that range, again because we have no efficiency percentage to tell us. It could be 50% efficient for all we know.
Second, their PureOne filter, their top of the line filter.
I couldnt cut and past their PureOne info but they list it at 98%. Seems pretty close to absolute efficiency, I would even give them the benefit of the doubt and say it is. However, what good is that benefit if there is no particle size number, I cant accurately judge the effectiveness of the filter. It could be 98% at 10, 20, 30, 40 microns or worse, we just dont know. Furthermore, they didnt give any details on the filter media either so we have nothing, at least from their website as to whether the filter is a paper filter or a synthetic media filter.
A surprise in the field, Motorcraft:
Part Number FL2005 Diameter in Inches 2.98 Length in Inches 4.72 Thread Size 3/4 - 16 ADB Valve Material Silicone RVOP Setting PSI 11.6-17.4 Efficiency @ 20 Microns % 95% Capacity gr 20 Burst Pressure PSI 200
What do you know, a surprise. Both a particle size rating and an efficiency rating. Hold on while I catch my breath and get my heart rate down
Now, NOW I can make an apples to apples comparison. Incidently, the above filter is for the 2000 Ford Focus w/Zetec motor.
If you compare the above information to another that gives the same info, i.e. Amsoil, then you can compare the two filters accurately and make an informed decision as to which filter is going to offer the most protection for your engine.
Heres the info for a 2003 SOHC Focus:
Part Number FL400S Diameter in Inches 2.98 Length in Inches 4.72 Thread Size 3/4 - 16 ADB Valve Material Silicone RVOP Setting PSI 12.5-18.5 Efficiency @ 20 Microns % 80% Capacity gr 7 Burst Pressure PSI 200
Oh my, only 80% at 20 microns. Not necessarily good, but I will give them credit for being open with thier numbers. Hats off to Ford. Unfortunately it only gets worse for you 2.3L owners.
Part Number FL910 Diameter in Inches 2.98 Length in Inches 3.33 Thread Size 3/4 - 16 ADB Valve Material Nitrile RVOP Setting PSI 11.6-17.4 Efficiency @ 20 Microns % 50% @ 35 microns Capacity gr 6.5 Burst Pressure PSI 217
Again, they are honest with their numbers and they deserve credit for that. However, Im sorry but 50% at 35 microns is pretty lousy filtration. These are paper filters as well.
Anyone running the 910 filter would do well to get rid of it. If its only 50% efficient at 35 microns, that efficiency is only going to get worse as the particle sizes get smaller. Granted we dont know if its a single pass test or multi-pass test but just the same and in either case, the numbers are not good.
Again, however, I want to say that Ford ought to be commended for listing the information they do. At least you can make a comparison. Their filter ability may leave something to be desired but their openess is on track.
____________________ My car is a synner! It uses Amsoil Synthetic Lubricants.
2001 Pontiac Grand Prix GTP
It whines a lot, but I like it
I don't think I woulda considered it if I had one of the other engines!
