OK . . . so I bought one. I know what everyone (or most) say about performance gains or mpg gains. But I got a super deal at the parts store, someone ordered one for a 2002 Civic and never picked it up. So I measured my '95 Civic, it was within a 1/4 inch all around, and bought it in the box for $15, oil and all. After I trimmed off the excess rubber, it fit perfectly. Now my question . . . directions say to spray the oil from 3 inches until it’s covered, no dry spots, then wait 20 minutes and drive. My question is . . . how much is too much. I sprayed a light coat, my thinking is that it’s just like an ordinary paper filter so too little can’t hurt, too much might. Anybody have any suggestions? I’ll let you know if my mpg goes up 25% or I spin the tires off of this little 1.5 rocket. Rocketman
This is tricky, because over-oiled may damage the MAF sensor if your car has one. But, it is the oil that does the particle trapping, not the cotton gauze. In a paper filter, it is the paper weave that traps the particles. I think a light spray of oil is all that is required. The 20 minutes is to allow the oil to wick across the gauze, I believe.
Well I guess you know at least partly why most of us don’t recommend them.
After I trimmed off the excess rubber, it fit perfectly.
That would scare me right there. You had to trim off part of the filter to make it fit. Yea, that sounds great.
Sorry about those vague instructions, but frankly that is about the best anyone can offer. If your idea of “spray the oil from 3 inches until it’s covered, no dry spots” is different than theirs, then I guess you could damage your MAF. That is why I and many others recommend not using them. Of course there are users who have not had any problems … yet. 
If you bought it new, then it’s already pre-oiled. You don’t need to put more oil on it. You only reoil it when you clean it.
The oil has a dye in it so you can judge the coverage. Like FoDaddy said, they are usually pre-oiled when new. When re-oiling after washing and a thorough dry, you spray each pleat from one side and let it sit for several minutes to soak up and distribute the oil. Then you look for remaining white parts of the filter, particularly on the opposite side, and touch it up.
I’ve had a K&N aircleaner on my 98 Chevy S-10 4WD w/4.3L V-6 for two years. There has been no appreciable increase in gas mileage or power, although it accelerates like a jack rabbit with a coyote on its tail. Of course it always has. Cleaning and re-oiling is a pain and not worth the effort or cost for no improvements.
That’s what I would have thought Joseph, if it had been an exact replacement. The filter I bought was for an '02 . . . my car is a '95 . . . before I bought it I checked the dimensions out on the K & N website and it was very close . . . within a 1/4 inch. I trimmed the '02 filter a little bit to fit my '95 and it fits perfectly. I have no illusions about fantastic performance but wanted to check it out myself. I’ll let you guys know if I get better mpg or performance. Thanks for your input! Rocketman