The reasons they are considered "high flow" air filters is because they flow more but do that at the extent they won't filter the smallest particles as would a cheap paper filter. You can clearly see that by looking at them. That's where the oil comes into play, the oil will help catch particles the filter misses. That's why when using a reusable filter it's important to oil after cleaning. I recommend getting the oiled one.
1998 Bright Atlantic Cobra - 3:73's, BBK ls, Pro 5.0, 96 Cobra STB, Borla XR-1 Catback, Custom Catch Can, Spec clutch, MM Firewall adj, FRPP wires, RSD, Spoiler delete, 245/275 BF Goodrich g sports on chrome 95 cobra r's
1998 V6 Mustang : SOLD!