Larger oil filter for better FE?
 

I looked on EcoModder for info on this subject but didn't find any. Anyway, since a cold motor may actually pass oil thru a by-pass valve until it is warm enough to pass through the filter media it occurred to me that using the largest oil filter that will fit your vehicle should benefit FE since it takes energy to push the oil through the filter media.

Can anyone give me an opinion or better yet, actual numbers on how much this might benefit FE?

Lighter weight oil is definitely better for FE but there is a limit to how light you can go.

I never heard of a thermostat setup on just a basic engine. I've heard of them with oil coolers.

Well, what my question is, do you think a larger sized oil filter would be FE beneficial rather than a small sized oil filter? I am not thinking in terms of doing anything to heat the oil, just wondering about the FE advantage of a larger filter.

Some engines, such as my 4 cyl. GMC Sonoma, come with a very small oil filter. I just finished cutting the motor mount area as required to accommodate the longer filter. My initial reason was simply to provide more filter area for the collection of dirt, but then it occurred to me that a larger filter should also make it easier for the engine driven, power robbing, oil pump to push oil thru it.

I wouldn't think it would result in much of an improvement in fuel economy. Your oil pump still has to force the oil through the engine and that pressure is going to make the oil filter pressure drop pale in comparison. Also most engines have a bypass valve that allows the oil to bypass the filter once the pressure across the filter reaches a certain limit.

I would think that the better filtration would lead to reduced wear on the engine. This better protection would keep the engine running better for a longer time and that would in turn improve FE.

My guess would also be that the resistance of the filter element is rather puny compared to the total resistance of oil flow.

But, just the fact that there is a bypass, in case the filter is plugged, or I would also assume in case it's 'just too cold', shows that the filter can offer a real resistance to oil flow.

I notice that my oil pressure is always up around 80 psi when I start, regardless of RPM, and gradually reduces to 40 or so once it is fully warmed up (1/2 hr. driving time). But since it is at 80 psi no matter the RPM I have always assumed it is likely flowing the oil thru the bypass, at least when above idle speed. This is true even when using 0W-30 Mobil-1.


It must take some HP to push that oil but like you say, the filter itself is probably a very small amount of the total oil flow resistance.

AirCooled VW's had an oil cooler thermostat :-)

I don't have scientific data, but I would change my oil in the supra when the mpg dropped 2 tanks in a row from expected, then it would return. Could be psychological.
I'm running an oil guard on the Golf for just that reason.

The size of the filter is just that, the size of the filter. The filter media is the same for the particular oil filter type and brand and would have nothing to do with the pressure required for the flow of oil.

I know that some Neon guys use Viper filters. If you change your oil every 3K, I don't see the benefit to going larger. However, if you're using extended-interval synthetics, a filter with a higher capacity could prove beneficial since the oil and filter would reach the end of their service lives at about the same time.

He's not talking about a thermostat. Cold oil is more viscous, thus causing a higher pressure differential across the filter media. To ensure sufficient flow and prevent media damage/blowout, a spring-loaded bypass is provided so the oil can bypass the filter and continue on to the galleys.

A larger filter would have more square inches of filter media. So that means when the same amount of oil passes through the filter, the velocity through each pore is less because there are more available. So less pressure is needed to push cold oil through the filter and less use of the bypass valve. Also the filter will stay cleaner longer since there is more media to fill with the same amount of dirt.

Not sure how much of this actually comes into play with regular change intervals.

But I mainly just use bigger filters on my cars because they are a lot easier to get a hold of with the filter wrench. I use the longer 3980 rather than the shorter stock 3387A.

I use a regular filter but I change it, and top off the oil, at about 1000 miles. It just makes sense to me to keep a clean filter on it. I just grab a Fram at Wallyworld for like $4. My filter is right on the front of the engine. So no sweat involved. I change the oil completely when it looks and FEELS dirty, which is a long time with all the clean filters going on.

I have only put ~12,500 on my car since Sept 04 and 2,500 of that was driving it from where I bought/rebuilt it.

Hello -

Don't know if this will help, but I read about one dude who claimed he got more HP on his racer when his oil level was lower. Based on that lesson, he lowered the oil level on his Saturn by increasing his filter size. Because the filter is bigger, the dipstick reads 1/2 pint less.

CarloSW2

I own a small industrial filter company, and I just switched all the oil filters in my small fleet of company cars over to a longer oil filter. I drive a Toyota Echo and didn't have to make any modifications to the car to make the change. Since I work in the filtration industry, I thought I'd share my reasons for doing so, as well as some of the technical aspects of switching to a longer oil filter for any that are interested.

First off, I recommend checking the specs of your new filter with the filter manufacturer's tech department before making the change, as you can damage your car if you accidentally put a filter on there with a higher bypass setting or micron rating than what the OEM recommends. Also, it's possible you will void your car's warranty by using a filter that's not recommended by the factory. I suggest sticking with a high quality filter OEM such as Baldwin, Mann, or Donaldson. I'd probably avoid Napa or Wix.

My second recommendation is to fill your longer oil filter half-way up with oil before installing it. If you can't do this, you may want to stick with the original filter. Otherwise, you car will run "dry" on startup (very little oil in it) a little longer than usual. This could damage your engine.

I changed from a Baldwin B33 oil filter to a Baldwin B7238. I double-checked with the factory and compared the surface area of the two filters (this is probably the most important spec), as well as making sure that the internal bypass valve and micron rating were the same between the two filters. Basically, the two filters were the same, except one filter had 88.6 square inches (B33) of media, and the other had 163.8 square inches (B7238).

The reason that surface plays such a big role is because it lowers the pressure drop across the filter. And yes, this pressure drop can be substantial (I think up to 20 psi when dirty - same as the bypass valve setting). Not only does this reduce the amount of work needed to pump oil through the filter, it also allows the filter to remove particulate more efficiently and operate effectively for a longer period of time. In fact, the biggest reason I changed to an longer oil filter wasn't to improve MPG, but to improve vehicle performance during extended oil-drain intervals. In other words, if someone went 2500 miles past the usual oil-change point, the filter would still perform well.

However, I have noticed a very, very slight increase in fuel efficiency, although I have not measured the difference scientifically. I've purchased a ScanGauge II from amazon and plan to try and test the difference the next time I change oil. I doubt if it's a huge difference at first, but might become more noticeable the closer the car is to an oil change.

In the long term, it will definitely improve the cleanliness of your engine and keep your car running longer. That in itself is probably justification for the mod.

Also, this can be a relatively inexpensive mod. In my case, the longer filter only took the investment in time to make sure everything was kosher, plus an extra buck or two for each filter.

Hope this is helpful.

trask768 -

Welcome to EM and thanks for the feedback! I like the "safety first" information. I didn't know about half-filling the filter with oil during installation.

CarloSW2

Having oil analysed and safely being able to go another 1000-2000-3000 miles leads to less oil purchases at the store, leaving decent money saved with no mpg change. I use 5.0 mustang filters on my toyotas, and on my neon. This aspire is a tough one to use a larger filter (honda's thread) and it's just a few ounces difference.

One of the first things my dad taught me about cars was to fill the new oil filter before installing it. Also to but a little clean oil on the rubber seal for a good seat.

I've always heard a larger filter drops your oil pressure once warmed up, also that it takes more oil to fill to capacity, becasue of larger size in which case the engine has to move more oil through the engine, which can then cause more work for the pump(which would cause worse mpg's) or heat problems(like in old vw's where if you put a deeper sump without a deeper pick up the cold oil would sink to the bottom and the hot oil would float on top of the cold and be picked up again and recirculated till the engine overheated.) There's more oil to cool, will that small amount make a difference? I don't know but those are the theories i've heard. Don't flame me:D just putting in what i've heard. Also there would be more oil to warm, so wouldn't it take a little longer to heat up thus also causing lower mpg's?

VERY helpful, great information. I have a question about your conclusion regarding losses associated with a relatively more restrictive filter:

If my bypass valve pops at 20psi, and while running at hiway speeds my engine sees about 40psi, then my oil bypassing the filter most of the time, right? At idle, my oil pressure might be 15psi, bypass valve closed, thus only filtering my oil while I am at a stop light, right? If that's right, then the only time I could possibly be using less power to turn my oil pump is when the pump is putting out less than 20psi, so I only save fuel under low loading situations, do I have that right?

With more filtering area you should be able to go more miles between filter changes if you wanted to, and reduce your chances of a clogged filter like you say. The old O-Berg aftermarket filters used to have a pressure sensor option, 'tattle-tale' they called it, to notify the driver of a greater than 15psi pressure differential across the filter: If the car builder wired it up right, when the separate filter idiot light comes on, it's time to clean the filter. Those were ok filters, just not enough square inches. Most racers I know have gotten away from that and gone to a System 1 or similar pleated stainless steel screen type filter. With or without bypass is still debated.

responses to last two posts
 

A bigger oil filter is not going to cause an oil pressure drop. In fact, it should help an aging oil pump perform better, as it is easier to pump the oil through the filter.

A bigger oil filter will slightly increase how much oil it takes to reach capacity - however it's very small difference (in my case about 1/2 cup) and easy to either compensate for the difference by adding extra oil or, in my case, ignore entirely since my oil level indicator still showed full.

You aren't moving any additional oil through the engine. Your oil filter should have an anti-drainback valve to prevent oil from escaping the filter when the engine is off. Your pump will have less work to do since it will be easier to push the oil through the filter due to the greater surface area of the filter.

You aren't exposing the oil to any additional sources of heat, so the larger oil filter will not cause any heat problems.

That's a common misconception about bypass valves, although your conclusion isn't necessarily incorrect. They don't operate on system pressure, they operate on differential pressure, which is the difference in pressure between the inlet of the oil filter and the outlet of the oil filter. Under certain conditions, a very dirty OEM filter may have a 20 psi pressure drop. Under the same conditions, a longer filter (with double the surface area) would probably have around a 8 psi pressure drop. Pressure drop across a filter is directly affected by several variables - as you increase these things, you'll increase the pressure drop across the filter: viscosity of the oil, flow rate of oil through filter, time in service of oil filter. However, there's an inverse relationship between the pressure drop across the filter and the surface area of the filter. In other words, as you increase the surface area of the filter, you'll decrease the pressure drop. In addition, an increase in oil filter surface area will actually decrease the effect that higher oil visocities, higher flow rates, and longer time in service will have on the pressure drop.

You definitely want a bypass on your oil filter, especially for racing. Without a bypass, as it gets dirtier, an oil filter will restrict flow more and more (and decrease oil pressure more and more) until eventually, your engine is so starved for oil that it locks up.

I've read about them. Good stuff i reckon, if not a little strange to be filtering with toilet paper!

ollie

I'm using a Pure One PL30001 filter on a 1.5L Toyota engine. Also trying Mobil 1 0W30 synth oil. Expect to run this a full year...with maybe a filter change midyear. Will probably add 3 qts oil over the year?

I consider this a cheap to use and install bypass filter.

The filter on the left is the regular NAPA filter for the car...the one in the middle is the Pure One version for the car...the one on the right is the PL30001 "Mustang" filter.

http://www.nonags.org/members/nijqk/3filters.jpg

While this is probably a fine oil change strategy, it is not a bypass system.

Bear in mind that you will probably never plug that filter, even over the entire life of your engine without filter changes.

How many miles are you driving per year? 3 quarts seems like a lot to me, any leaks?

Also be sure that your filter has the proper valving (drain back, bypass, etc)

If you want a true picture of your engine/ oil send off a sample to a lab.

bigger filter brand name and part #
 

trask 768 how about some part numbers on those filters, i might like to try one as i also drive an echo.

...whenever possible, I've always tried to use the "...largest size..." oil filter available, often one labeled as being for a truck.

...the bigger size usually means less backpressure resistance, longer life, bigger filter area, and slightly longer oil life.

Not technically a bypass filter...but a cost effective way to get closer to one.

The By-pass Oil Filter. The Ultimate Oil Filter.

"A regular oil filter will filter out dirt and contamination particles to about 20 microns in size. The AMSOIL Ea nanofiber oil filter will filter out dirt and contaminants down to about 5 microns in size. If you add the AMSOIL By-Pass filter system to your vehicle, it can filter down dirt and contaminants to 1/10 of a micron. You will get tighter clearances, better engine performance, and much longer engine life!"

My car uses around 1 qt per 5K miles...so over 12K it will use at least 2-3 qts espec if I change the filter one time.


Amsoil EAO vs PureONE - Topic Powered by Social Strata

" I've searched the forums and it seems that people choose the Amsoil filter over PureONE on 'faith' that the Amsoil brand is somehow better than every other brand.

After checking the specs for the Amsoil EAO filter and the Purolator PureONE filter I found something shocking... PureONE is actually better by the numbers.

According this this website: AMSOIL - AMSOIL Ea Oil Filter (EaO)

"Amsoil tested their EAO with the industry standard ISO 4548-12 and found that the 15 micron efficiency to be 98.7%

PureONE's ISO 4548-12 for 5 micron is 50%, 10 micron is 92.8%, 15 micron is 99.2%, and 20 micron is 99.9%. [info source: e-mail response from the tech/engineer department].

I've e-mailed Amsoil about the 5/10/20 micron ratings that isn't listed on the website but it would seem that PureONE is better than Amsoil by the 15 micron comparison.

So... PureONE's filter is not recommended for 25,000 miles oil change but Amsoil's EAO is by what logic? I guess if you trap more particles you have to change out the filter more often which means that the Amsoil one is probably letting more things through so it doesn't clog up and go into by-pass valve mode."

It's possible that the Amsoil filter has more filter media to hold the crap before it reduces flow too much. The Pureone's are very good filters, of course, especially when you consider the price. I can get one for my Jeep for $6.50.

I run 10K per change on my metros with a ph3600 filter (typically found on ford 3.0 V6) Its the largest filter that fits with A/C on the engine. It increases the oil capacity by 1/2 qt. which makes me feel better knowing that there's an extra 1/2 qt in there if it ever gets low :) More dilution for the filth from the engine plus larger surface area and capacity. Its all good :)

That's not correct. X quarts stock system capacity + 1/2 quart added filter capacity balanced against X quarts + 1/2 quart added to fill the filter equals the same oil level in the sump. Getting low is thus the same condition -- you do not have an extra 1/2 quart of margin.

Sorry, not my intent. I don't care about level, I was thinking of total oil in the system. the metro only holds 3.5qt, and I feel a lot better knowing that if I'm a qt low there is still 3 in the system instead of only 2.5. A qt low is a much smaller percentage of 4 than 3.5. Its not margin, and I know that the extra 1/2 qt is in the filter not in the pan.

The way to think about it isn't as safety margin, but as keeping the stuff more diluted. More oil volume allows longer time until change, due to slower additive depletion, etc.

In that context, the only way having an extra 1/2 quart would be beneficial would be damping spikes or drops in oil temperature. Is that your intent?

no, more what comptiger said,at 1qt low I'm down by 25% capacity instead of almost 30% better dilution of contaminants and more additives present, especially since I go about 10K between changes. Oil pressure/temp? I don't know why I'd be concerned about that at all in daily driving situations.

On any engine I've seen or heard of, the oil pump is connected directly to the pickup tube that draws from the pan. The oil is pumped through the filter under pressure, although the sender for the gauge is after the filter, so a restricted filter will show as lower oil pressure. The can on the filter is surprisingly strong, and most can handle over 100 psi of oil pressure without bursting.

There have been rare occurrences, however, of filters exploding when a cold engine with thick oil is redlined, and so much pressure builds that the oil pump relief and filter bypass cannot flow enough to relieve the pressure, and the filter either blows off, or explodes.

That is incorrect. As comptiger5000 says, every engine I know of has the arrangement of pickup -> pump -> filter. I would be very surprised if you came up with any example of the arrangement you're suggesting.

As for the filter metal being thin, a can shape is far more likely to crush under vacuum than it is to burst under pressure. Under vacuum, the material is under compression and tends to buckle, whereas under pressure, the material is in tension and resists deformation.

Dunno what you're hinting about when you're talking about someone else hinting about something! :p

I'm still fairly new to all this but I would think the size of the filter really wouldn't do anything for you except allow a slightly larger amount of oil to be in your engine lubrication system at any given time.

Say, for example you use a Fram oil filter, no matter what size it is, they all use the same basic filter media. The only difference that the size makes is the volume of oil it holds.

Also the amount of crud the filter can capture before being full think of it as your motors trash can.

It's okay that you aren't sure of the benefits, you came to the right place for info! I work for the company that sells filter media to Honeywell(Fram). If you increase the size of the filter, the area of the filter media increases. The oil pump can only output a specific amount at a given rpm, that doesn't change. What does change is the differential pressure against the filter. At a given pressure and area of media, There will be a certain face velocity, or speed at which the oil hits the filter. If you increase the area of the media, while all the rest of the system stays the same, the face velocity decreases.
This has several benefits. First, a lower face velocity means better filtration, the particulate matter hitting the filter is moving slower, and has a greater likelihood of being captured. Secondly, a larger surface area decreases the back pressure on the oil pump with cold oil, due to cold oil having a high viscosity compared to warm oil. Lastly, though not the last benefit, the larger surface area means a greater capacity, so the life of the filter increases.
It depends on the line of filter, but I think I know what you're saying. The Fram Tough guard is tighter filter media than the standard media. The Fram Xtended guard is far superior in construction (metal end caps, expanded metal backing, dual-layer synthetic media, I know, I helped design it :D, though Honeywell has dropped the ball in the marketing department and doesn't advertise for squat - but that is another thread.) and has MUCH high capacity than the other media in the Fram lineup. So, if you pick up a regular Fram filter and then get a larger sized tough guard filter, the back pressure is probably going to be similar, due to the tightness of the Tough guard, but you will have a larger area and smaller pores (better filtration). I hope that clarifies the subject. Just ask if you have any more questions. I love this stuff, because it's what I do everyday! :thumbup:

pour point at zero-degrees
 

I took baby-food container samples of a half-dozen motor oils,from Honda's 0 wt-20,to 5wt-30,10wt-30,10-40,etc.,and placed them overnight in my freezer ,at 0-degrees F.
Next morning I pulled them all and did a 'tip'-test,turning all of them over simultaneously.
All of them essentially poured out within the jars at an equal rate.
From that observation I would deduce that the cold pumpability at the filter media is not a real issue for us.
Your pressure bypass may exist to 'maintain' oil pressure within the lubrication system,modulating between cold and hot conditions,and as the engine rpm( and pump rpm) varies from idle,up to redline.

Phil -

It's too bad you had no way to measure film thickness at freezer temperatures... that would have been an interesting comparison between the various oils.

Sorry, but dumping them out against zero resistance using uncontrolled pressure is a rather unscientific test. There are reasons why oil viscosities are measured using designated test procedures (ASTM D5293 and ASTM D4684).

Also, it's "W," not "WT" as oil isn't measured by "weight," but viscosity. The "W" denotes the cold-weather ("winter") viscosity. Otherwise, there would be a W after both numbers (i.e. 5W-30W) or the W would be at the end to denote a viscosity range.