Foam Air Filter WARNING

 Paper or foam?

 "Personally if I only had to choose between a regular paper air filter and a foam one I'd choose the paper every time." ~Jim

 Fortunately there are OICG (oil-impregnated cotton gauze) air filters that most high-performance applications and even helicopters use, that is my first choice, mainly for the better airflow characteristics.
There have been fit problems with the OICG and foam filters and even some paper filters as to fit on the GM 6.5 and other applications so proper installation and a good sealing filter is key to keeping the dirt out. 

 There are some rumors about higher silicon levels when oil lab tests are made and the rumors blame this on sand passing through the filters, a filter manufacturer says it's from the oil used on the filters having silicon in it, but I have not seen any data to support either claim and it appears to us that the silicon level myth is just a scam to sway buyers to other filters.

Having run the OICG type filters since 1978 our fonder Jim would know if any sand passed through the filters, and with over 150,000 to 200,000+ miles on many vehicles in that time and various engines disassembled for inspection or modifications and no indications of grit or sand passing through the filters or engines.

Now here is a real WARNING...

If you are considering a foam air filter, here are a few things to think about...

  1.  Foam has tiny crevices and those get plugged up easily but are hard to clean so the flow of the filter after cleaning decreases over time as compared to the new filter.
  2.  Foam is not the best idea for filtration, think about it, what good vehicles or engines use foam filters from the factory?  All that usually comes to mind is lawnmower engines, as an example we had 2 vintage 1980's walk behind self-propelled lawnmowers, both are made by Snapper and feature Briggs & Stratton engines, one is a regular duty 4hp and it has the cheap foam filters that plug up and eventually fall apart, the other machine is a 5hp "commercial" unit and it has a canister paper filter, my point being even lawnmower and small engine manufacturer's know to filter better for long term reliability foam is not the way to go.
  3.  Did you ever notice that almost no popular makers of; high-performance vehicles, aftermarket performance shops or manufacturers of performance air intakes use the foam filters? in fact we know of none, there is good reason why they don't use them.
  4.  Foam is really only good as an outer layer if you need added filtration for an extra dusty or extreme conditions, and then the quality performance filter makers may offer foam as an add on outer layer over paper or oil impregnated cotton gauze (OICG) type air filters.
  5.  Additionally, if a pictures says a thousand words, below is a picture of a lawnmower foam filter after not all that much use and it failed, and let unfiltered air and dirt was pass right in to the engine, worse still the dirtiest and most abrasive deteriorated parts of the filter get sucked in to the engine as well.

  It's not too difficult to imagine the horror you'd feel if a dirty foam filter deteriorated and emptied all the dirty contents, it held for who knows how long, in to your expensive turbocharger and expensive high compression diesel engine. Even if lucky enough not to have it fail completely, just a tear can let a lot of dirt that built up on the filter and other unfiltered air pass. Air like water tends to follow the path of last resistance or least restriction, so the majority of air would enter the hole or tear and rapidly wear away the foam to make a bigger and bigger path, as shown in by the photos below.

                        Foam Air Filter desinigration and failure
Picture is of the under side of a failed lawn mower FOAM air filter. The Commercial version uses a Paper filter!

                        Foam Air Filter desinigration and failure
 Picture is of the top side of a failed lawn mower FOAM air filter. The Commercial version uses a Paper filter!

 So if someone is trying to sell you a performance air filter, make sure you ask what the media material is, and if it is foam, RUN!

 I would seriously question the credibility and actual experience in the automotive business of anyone recommending one of those foam filters for your turbo diesel engine.

 Fortunately foam filters are not too popular, and for good reason...

  Foam is definitely out, so what then, Paper only?, or what else?
You may want to consider a Hi-Flow oil impregnated cotton gauze (OICG) type air filters, better flow for better breathing that should result in power and mpg gains.

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