I just looked again in my 2020 owners manual in the maintenance schedule chart and it makes no reference to a time limit for air filter replacement, just a 45K mile replacement?

 

Referring to the air filter percent life monitor which seems to count down based on time and expire at 4 years.

 

The 4 year requirement is in one of the footnotes of the maintenance schedule.

 

I don't think the 2020 has the AF life monitor. I've never been able to find one on mine. Has any other 2020 owners found one? if so, where in the software?

 

The 2020 doesn't have an air filter life monitor.

 

I found it, not that I agree with a 4 year requirement. I'll just be around 14K miles after 4 years.

 

I keep seeing statements that it defies the laws of physics to have a filter that can meet the same filtration requirements but have a lower pressure drop which isn't true. There are different approaches that can be combined with a meadia (centrifugal, electrostatic, etc.) to achieve the same results with a lower pressure drop. A simple approach is to use the same media with more surface area (i.e., deeper and/or more pleats).

I'm not saying any of the aftermarket filters have the same filtration capability as the OEM filter, I'm just saying it isn't impossible.

 

[QUOTE=Maxie2U;1607470692]Your air filter life is surprisingly low given model year and mileage. I have 7030 miles air filter life @ 68%. Model year 2022.

BTW, Attack Blue air filter is a complete waste $$$$ it marginally increases HP unless you track your car where any increase in hp is wanted. Also a less restrictive air filter means LESS FILTRATION anyone who says otherwise simply bought into the Attack Blue hype and marketing. Attack Blue’s marketing slogan is, “More Air More Power More Filtration”. Somehow they figured out how to defy mechanical engineering.[/QUOT. Your filter @ 68% explains that both time and mileage are factors.

 

I agree it seems very conservative. There are people that just use a pressure drop monitor and don't change the filter until they see a significant pressure drop. While a pressure drop will affect performance at WOT modern fuel injection systems compensate for it so the fuel mileage doesn't decrease.

It could be the media breaks down with moisture, the adhesive securing the media breaks down, the seal gets hard, etc., we don't know. I normally inspect a low mileage filter and CAREFULLY blow it out with compressed air. However, as long as I have a warranty I'm going to follow the GM's requirements.

 

I'm not saying any of the aftermarket filters have the same filtration capability as the OEM filter, I'm just saying it isn't impossible.

While what you posted is obviously true but there is nothing available using the "advanced" technology you sited so let's say there is nothing available on the market today since all current car intake air filters involve paper filtering technology. And that technology has advanced significantly over the past decades.

 

As a retired mechanical contractor and Mechanical Engineering (HVAC) technician I worked quite a bit with all types of filtration, design and application. As you said, increasing the amount/depth of pleats will increase flow, assuming it's with the same comparative filtration media. It's about the degree of face velocity of air impinging on the filter media. Each media has its limits on face velocity also. If the face velocity is too great then the air will "pull" particulates through said filter. This is also a biggie with HVAC filtration systems, hence the birth and application of pleated air filters. That all being said, increase the amount and depth of the AF pleats where the filter media has a face velocity that's below the threshold of where particulates are pulled through and you're good as gold. Each different filtration media has its own max face velocity, dependent of type (cloth/paper/synthetic/oiled/dry), application and lastly thickness. The CFM passing through is also a major player. Conclusion; A well designed aftermarket air filter can be just as efficient and permit minimal particulate transfer as an OEM paper one. This is NOT saying they are though.

 

The Attack Blue (and perhaps others) uses nano filter technology. This could be combined with changes in pleat design to provide effective filtration. Nano filters can also be combined with electrostatic fibers.

Again, I'm not saying that the Attack Blue (or other filters) filter as good I'm just saying it isn't impossible.

 

The stock filters in Corvettes have used "nano filter technology" with many more pleats than aftermarket for a least the last 3 generations.

 

Filters made from media using nanofibers are different from cellulose filters which nearly all OEMs use. Increasing the number of pleats doesn't make it a nanofilter. However optimizing the number of pleats could be used for the nanofilter media.

 

Interesting discussion but show me a serious study, with metrics, that indicates a Blue is as efficient and allows more air. A serious study is not a graph from the maker...that is marketing.
The study I linked above covers nano technology and shows the metrics they utilized. They still concluded more air= more particulate matter regardless of the material. The Nano fibers, if too dense clog quickly so they only as an application over a cellulose filter.... if the nano fibers are not as dense, they allow less filtration. More filtration=less air.

The issue with mid engine cars like ours is the air inlets are on the side...iow, everything your front wheels kick up have an opportunity to be scooped up...especially fine dust that exists everywhere. This is especially an issue in the dry SW where I live...if a quad goes by on the side of the road the dust simply hangs in the air. I want the best filtration I can get and that appears to be cellulose. I will change my filter every 7k.... it is an easy job....and cheap.

 

Admittedly I didn't go through the study in detail, there is a lot of information there. But the study seemed focused on the media and I didn't see anything that described any optimization of the configuration to take advantage of the properties of the nanofiber media.

The main problem with nanofiber filters seems to be they load up quicker. In industry they periodically puse the nanofilters to clear debris. A car's intake naturally pulses in certain operating conditions and I didn't see that discussed.

But I completely agree that there isn't enough information on the Attack Blue filter on the website to determine if it actually filters equivalent to the OEM filter. Standardized test results (especially loading tests) need to be shown that compares their filter with the OEM filter. And it would be good to have comparative results in the actual operating environment. It could be that it initially filters good but needs more frequent maintenance to maintain the performance advantage.

 

I agree....about the lack of actual testing other than a marketing attempt. Down in the study I linked they discuss and use a nano filtering device over a conventional cellulose filter...probably due to the loading you mentioned.
As I've never seen any claim of equal or better filtering than a cellulose filter (the Blue admit to less filtering in the abstract but do not really define that other than a percentage point) I can't imagine less material/more air equaling more filtration.
If one uses the Blue then whatever metrics are in the C8's bank for filtration usage is also moot....and I think it overly optimistic anyway so will ignore that message and change mine out on my own schedule.

 

GM has had the 4-year requirement dating back to the C5s, not sure about anything prior to that (I haven't checked). Paper degrades when exposed to the elements (humidity, heat, etc.).

 

Question...has anyone left an air filter in place for 4 years? Regardless of mileage?

 

A friend's dad left the factory air filter in his C5 for more than a decade (only had ~10k miles on it) and it was seemingly fine. I left an air filter in a Chevy Volt for 4 years and it was seriously degraded/deformed and almost crumpled up looking.