10k miles and still nothing.
Installed a filter minder
- Thread starter oil pan 4
- Start date
Unless you’re in a very dusty environment, you’ll be surprised how long the air filter will last. Even if the filter looks dirty doesn’t mean it has a lot of restriction. Keep watching it.
You probably won't see it move for a very long time. The problem with these filter minders is that their range is usually too high for most applications.
A filter should be changed after a dP increase of 8-12 "H2O, or even sooner if you want to prioritize engine performance. A new filter will usually start out at around 1-2 "H2O, but the air box could potentially add some significant restriction to the reading as well, and you won't know what the baseline is with a gauge like this. I've seen a version of these with a range of 3-11" H2O, which I think would be better for most cars. Changing the filter at just above 10" is a good plan though.
Since you inspect the filter at every oil change, you could weigh it on a kitchen scale every time to see how quickly it's picking up dirt. The holding capacity should be at least 100 grams. I've weighed my car's filter a few times, and I expect it to go well over 100k km before it even hits 50 grams. Most filters get changed far too early.
You would really need to weigh it before the install to have a baseline measurement to go off of. Even another filter exactly like that would probably weigh more/less.
Also the size of the particulate matter that it catches would make a difference. Coarse sand vs ash. The filter minder is the only way to know about the restriction.
If a restriction gauge contrary to expectation doesn't indicate increasing restriction over time I would investigate if there's a leak creating a bypass. Do you guys clean out the gasket seating area when changing an air filter? If the sensitivity of the gauge is inappropriate for the application, why use it in the first place?
This is a good discussion of experience with restriction gauges. Measured performance beats speculation. I have installed filter minder gauges on all the light duty vehicles which I service and I have not replaced an air filter since the gauges were installed. If the vehicle is used predominately on paved roads, filter life should not be based on time or mileage. If air ducting and filter seals are not leaking, dry air filter efficiency improves with use. I do check the filter seals every few years, wipe the sealing surfaces with a damp clean cloth and vacuum the air box and dirty side of the filter being sure not to disturb the media.
The best air filter document that I know of is "Nanofibers in Filtration Applications in Transportation" given by employees of Donaldson Company in 2001. Here is a quote about consumers and light duty vehicles:
"Consumers must also make maintenance decisions about the air filters in their cars. This user group is relatively unsophisticated in their knowledge of filter maintenance and function. Air filters are perhaps the most easily serviced but least understood part of the vehicle. Other common replacement parts on a vehicle such as tires, wiper blades, oil and oil filters work best when new. However this is NOT the case with conventional air filters. Since most (dry) air filters rely on the formation of a dust cake to improve the performance of a filter media, over-servicing can lead to dire consequences from inadequate engine protection.
Over-servicing is common in light vehicles. Light vehicles are generally not equipped with filter restriction indicators. Air filters are often inspected by maintenance personnel during oil changes. In spite of the typical manufacturers recommendation of at least a 30,000-mile change interval, it is common for dealers and quick lubes to recommend more frequent air filter changes. Given the frequency of oil changes and air filter changes at quick lubes, it is expected that many light vehicle (air) filters are changed much more frequently than manufacturers recommend.
While this over-servicing is frustrating to those who understand filter media performance, the filter industry has not sufficiently educated customers on how air filters function. Not surprisingly, filter manufacturers, distributors, dealers, service stations and quick lubes have economic incentives to change and sell more filters. It is also understandable that consumers believe that filters work best when they are new (like other parts) and have a clean appearance.
In spite of the best intentions of automotive mechanics and consumers, typical automotive air filters are notably inefficient at capturing particles less than 5 microns in size. Several studies have shown that particles between 1-5 microns cause engine wear, which will lead to increased engine emissions and shorter engine life. Because many car engine air filters are over-serviced, a typical automotive filter may operate most of its life without the protective benefits of a well developed protective dust cake. As the filter becomes dirty by visual appearance (and the dust cake finally starts working) the filter is often exchanged."
No one except heavy duty filter manufacturers will give you this advice, but it is absolutely true and has been verified with numerous engineering studies and my own experience monitoring industrial dry dust collectors.
The best air filter document that I know of is "Nanofibers in Filtration Applications in Transportation" given by employees of Donaldson Company in 2001. Here is a quote about consumers and light duty vehicles:
"Consumers must also make maintenance decisions about the air filters in their cars. This user group is relatively unsophisticated in their knowledge of filter maintenance and function. Air filters are perhaps the most easily serviced but least understood part of the vehicle. Other common replacement parts on a vehicle such as tires, wiper blades, oil and oil filters work best when new. However this is NOT the case with conventional air filters. Since most (dry) air filters rely on the formation of a dust cake to improve the performance of a filter media, over-servicing can lead to dire consequences from inadequate engine protection.
Over-servicing is common in light vehicles. Light vehicles are generally not equipped with filter restriction indicators. Air filters are often inspected by maintenance personnel during oil changes. In spite of the typical manufacturers recommendation of at least a 30,000-mile change interval, it is common for dealers and quick lubes to recommend more frequent air filter changes. Given the frequency of oil changes and air filter changes at quick lubes, it is expected that many light vehicle (air) filters are changed much more frequently than manufacturers recommend.
While this over-servicing is frustrating to those who understand filter media performance, the filter industry has not sufficiently educated customers on how air filters function. Not surprisingly, filter manufacturers, distributors, dealers, service stations and quick lubes have economic incentives to change and sell more filters. It is also understandable that consumers believe that filters work best when they are new (like other parts) and have a clean appearance.
In spite of the best intentions of automotive mechanics and consumers, typical automotive air filters are notably inefficient at capturing particles less than 5 microns in size. Several studies have shown that particles between 1-5 microns cause engine wear, which will lead to increased engine emissions and shorter engine life. Because many car engine air filters are over-serviced, a typical automotive filter may operate most of its life without the protective benefits of a well developed protective dust cake. As the filter becomes dirty by visual appearance (and the dust cake finally starts working) the filter is often exchanged."
No one except heavy duty filter manufacturers will give you this advice, but it is absolutely true and has been verified with numerous engineering studies and my own experience monitoring industrial dry dust collectors.
Do you have a copy or link to that? I would probably read all of it.
I replaced the last air filter in my truck because the foam ripped, replaced the last air filter in my wife's cars due to poor fit allowing dirt past it.
I figure if the fit is good and the filters foam doesn't rip I'll run it till I see dirt on the inside of the air box. Which appears to happen when the filter is covered and saturated with dirt and this dirt appears to start migrating through the filter. Which appears to happen at some point after tens of thousands of miles and thousands of hours.
This is a very good read on air filters. Short and concise.
https://www.rv.com/rv/towing/the-truth-about-engine-air-filtersinternal/
https://www.rv.com/rv/towing/the-truth-about-engine-air-filtersinternal/
I have a few quams about that article.
It says "not automatically discount one type".
Yeah I would. Foam and oiled gauze are trash. I'd only run a k&n filter on a boat. Urethane foam, on a small lawnmower.
Paper is cheap and acceptable. Even the cheapest paper filter money can buy is going to stop about 97% of dirt on an iso5011 test. Its certainly good enough.
Synthetic fiber is where it's at, can't always get it for your app. Synthetic fiber filters catch better than 99% of dirt without even trying and flow air like they aren't even there. A gram of dirt per 500 miles is interesting, I hadn't heard that before.
The paper is a down loaded PDF which is not supported by BITOG. I have attached the air filter vs engine wear chart which was included in the original document. I will keep working on it.
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This tracks with everything I have learned in my 11 years at Fleetguard...for what that's worth.
Heck yeah. Science, not speculation.
Any added significant restriction from the intake system won't matter if the baseline dP measurementis done right. The dP gauge should be mounted on the clean side of the filter, close to the filter in the air box. The baseline restriction should be determined by seeing what the dP across the installed filter is when new at WOT high RPM. It will account for the filter and any added system restriction - ie, the intake system with filter. That will produce the highest air flow through the filter when new, and the most dP in the new filter. Then later after the filter gets loaded with debris, the same WOT high RPM run should be done to see the difference from the baseline run when new. So only the added restriction of only the filter will be seen.
Filter dP checks should be done at WOT and high RPM since that's the most demanding air flow senario. If someone never did more than crack the throttle while driving around, the air filter could probably go forever before producing 10 inches of H2O over the new filter baseline dP.
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Had 2 days of dust storms. Visibility less than a mile for the last 2 days and for several hours it was a lot worse, down to about 30 feet of visibility.
That should have loaded the filter up pretty quickly. Have you checked your filter gauge to see if it has moved ?
That looks like the one that is installed on my TRD supercharged Tundra that came with the supercharger kit from Toyota. Been on there since and dont think its ever moved.
Put a rag over the intake inlet and see if it moves. If it doesn’t or doesn’t move very much, then you may have a serious vacuum leak down stream.
It hasn't but I also haven't had a reason to take the engine much about 3,000rpm.
