I’m still using the original filter that came with my ViAir 450c
That’s about 5 years of hard use and the filter still looks new 
I’m in the middle of replacing some components and since it came with two extra filters, I’ll go ahead and change that too, but I’m surprised it held up this long…
i’d like to know this as well… mine have always looked like new, even after 2 years of use in my old 380c
oh btw where are you from snake? I saw someone with a cobra driving around with a vanity plate that said 98snake and though it might be you lol
i think its mainly for the compressors mounted outside of the vehicle…my friend has had his compressor mounted under his cummins covered in mud and never washed off for over a year now and it still runs fine
the location and type of filter have a lot to do with it.
his plates means he eats cobras…he drives a transam or camaro i guess…
Always inspect the condition of the filters. If they’ve been kept in a relatively clean environment, then your replacement interval will be few & far between. -That’s another side benefit to remote mounting the air filters. Otherwise, I’d check them every 2-3 months, especially in the Winter & Spring time. If you run through a puddle at ANY time, its a good idea to turn the pumps off, and check the filters. Moisture causes rust, rust & moisture kill perfectly good compressors.