All true, as you wrote. However, I understood the question to be truly extreme conditions. I have driven commercial and military wheeled vehicles thru volcanic "dust" finer than talcum powder and several inches deep on two separate continents and no system that uses a filter alone can handle that for very long. That same fine abrasive dust raises hobb with supposedly "sealed" lubricated moving parts as well. I've also logged more than 30,000 miles (so far) on extremely dusty erm, "secondary roads" (not your average gravel county lane - REALLY dusty roads). Larger, more robust vehicles (larger parts) have withstood more abuse than small trucks and SUV type vehicles in those environments in my experiences. It's not just the air induction system that takes abuse in those conditions, eh?

K&N filters and intake kits cover a lot of applications, but nothing I am aware of for those kinds of conditions. There are ready-made snorkle kits available for some smaller SUVs and trucks - IIRC, ARB may be one supplier - and they help get the intake above a significant amount of the dust. Other installations accomplish the job almost as well by routing the intake to inside the passenger cab, although those have more utility in intensely muddy environments (and deep snow, FWIW - I've had to remove snow from clogged intakes many times, as well as clear it out of the radiator to relieve an overheating engine).

The OEM air intake system and OEM filter elements on many of the newer full-size US trucks are pretty good - much better than the old style paper doughnut on the carburator. The old metal-mesh oil soaked OEM "heavy duty" filters were pretty lousy at filtering; their main advantage was that they did not clog up readily. Of course, those engines didn't last long between overhauls by current standards - properly maintained modern V-8s and V-10s will go at least 5 times farther (maybe more) before an overhaul than those old guys would. Ditto for the smaller engines, for the most part, although there are usually other drivetrain parts that give up the ghost before the engine on the smaller vehicles.

Still, I agree that replacing OEM air filters with a K&N kit is money really well spent, even for vehicles that never leave the paved road - if you keep the vehicle longer than the payments.

A workable alternative for dust is to carry a spare OEM filter and with on-board air one may keep things running by swapping them out and blowing out the OEM filter - not a great solution, but it works. Bad dust is like water, though - if you drive in it, you need to do a LOT of maintenance and re-lubrication of everything (especially including engine oil and filter) ASAP when you get out of those conditions.

Fortunately for me, I pretty much stay on pavement or gravel these days. New vehicles are too darned expensive nowadays...

Regards,

Tom