K&N Universal Clamp-On Engine Air Filter: Washable and Reusable: Round Tapered; 4 in (102 mm) Flange ID; 7 in (178 mm) Height; 5.375 in (137 mm) Base; 4.375 in (111 mm) Top , RU-2590

I have been using your RU-2590 universal filter on a 2000 Ford F-350 with the 7.3L diesel for many years. It seemed small for the application but it has worked fine. I am getting over 20 MPG (with other mods. also)so it's size has not restricted air flow. Diesel filters do require much more frequent cleaning than advertised - in my experience every 3,000 miles or monthly, especially if I have driven through rain. The rain washes the oil (and dirt) from the filter right into the intake and the turbocharger. I have been able to minimize this somewhat by using drychargers for the last 3 or 4 years. They do stop fines from entering into the filter element somewhat. During a recent replacement of glow plugs and a turbo rebuild at 370,649 miles, no wear was apparent within the turbocharger. I have used a 1 micron bypass filter and [brand] synthetic additive (2 oz./QT of oil every 30,000 miles) since approximately 11,000 miles so this has apparently contributed to the low or minimal wear (the magnetic drain plug is almost clean at oil changes). The only other thing I have noticed is that after 2+ years or 20 or so filter cleanings the rubber flange of the filters shrink a bit, become harder and will no longer fit on the 4 intake. I think I read K & N recommends +/- 25 cleanings before replacement anyway though.

This is a replacement for my original K&N filter. The original one is approximately 2 1/2 longer, making for a very tight fit in the space required. This replacement has more wiggle room, something I wanted. Thank you very much K&N!! Mahalo.