[Christ]

I've used the same stainless steel mesh filter by APC (Ya, I know) for over 5 years now. When it gets dirty enough that it doesn't look shiny any more, I just rinse it out from the inside, don't bother drying it, and reinstall it on the car. It cost me $20 on sale, down from $30 something.

I've used it on multiple vehicles, although it's a cone filter. I don't worry too much about noise under the hood, so the "growling" of the engine means nothing to me, and I remove the OEM airbox. There is usually no weight savings in doing this.

I've never experimented with warm air intakes, I've always pointed my filters to colder air locations, but I can't speak to FE gains or losses, since I never really recorded anything, and my "datafield" would be far from invariable.

I can say that switching from that filter to an open-cell foam *non-oiled* cone-type element on the same smooth intake pipe with no PCV, I got worse mileage SUBSTANTIALLY (like 3-5MPG worse.) and 0-60 took about 1 second longer. (1989 Civic DX, CAI, cat-back 60mm exhaust, open muffler, 3 angle valve grind and intake porting/polish, drilled fuel rail.)