If you have a turbo-diesel (newer Powerstroke, Duramax, Cummins), I'd look into the FRAM Air Hog (if your local stores have any). The Air Hog turbo-diesel models are supposed to have (8) layers of cotton media rather than (4) layers like a K&N. The urethane on the Hog is a lot harder/durable...
Mybe you should add the parent company name as far as who makes which filter brand, instead.
- FRAM = Honeywell
- Fleetguard = Cummins
- Racor = Parker-Hannafin
- Etc.
Also, Honeywell/FRAM supplies the Mack/Volvo truck OEM/OES filters and "Performax" (Shell's other brand) filters, too.
Actually, per ISO 5011 there are "choices". Contaminant ISO 12103-A2 (Fine) or ISO 12103-A4 (Coarse) test dust can be used (not sure about ISO 12103-A3 (Medium)).
Be careful when comparing performance test results. Variables such as contaminant type, dust injection rate, test termination...