[Lemotan]

This is how the inside of the air filter looks—there are some fine dust particles that appear to have made their way through. While the filter itself still looks like it could likely be used for a bit longer, I'm not used to seeing any dust traces on the clean side of the filter.

 

[Lemotan]

This is good to hear. I went all in on K&N for all my vehicles in 2024...but subsequently had been wondering if it was a good call. As you may be aware there are K&N naysayers out there...

My understanding is that K&N filters rely heavily on proper maintenance—the filtration is primarily handled by the oil applied to the filter, rather than the filter material alone.
I’ve done the oiling process a few times on a motorcycle air filter, and I’m not a fan of it.

 

[Lemotan]

It also depends on the climate—for example, in Louisiana, an engine air filter can still look nearly brand new even after a year of use.

 

[Lemotan]

I usually stick with OEM filters once a year, or go with a non-OEM option like Mann & Hummel if it's available.
I’ve watched multiple tests comparing K&N filters to standard dry paper filters, and unfortunately, K&N tends to let more micro dust into the engine—trading off filtration efficiency for a slight 2–3 hp gain. That might be acceptable for track days or if you live in a very clean, dust-free area, but not ideal for everyday driving where i live.

 

[Lemotan]

I read a post from a fleet mechanic who claimed they never replaced air filters—just blew them out with compressed air—and still had vehicles reaching 300K miles before being retired. That said, it only takes a single teaspoon of fine dust to cause serious engine damage.
As I mentioned before, it really depends on where the car is used. Some areas are relatively clean in terms of dust, while others—especially those with a lot of silica dust—can be much harsher on engines.