Oiled or not I’ve a question about them:
If they let more air in - which I assume they must to give more oxygen to mix with the fuel - they must have larger pore sizes if that’s the case then they potentially allow more dust/grit etc through the filter as well - would this not then have a detrimental effect on the engine over time ?
I too have a K&N panel filter on my car, I’ve always been extremely doubtful about these claims of how much it damages the MAF sensor by filter oil contamination! The link provided by John (cypher) goes a long long way to disprove these claims (IMO). The filter was on my car when I purchased it, along with the sticker, oil etc. I can’t judge whether it increases performance? Probably not but I like the idea of a lifetime filter and won’t be changing mine in the foreseeable future. Not sure I’d go out of my way to purchase and install one if it hadn’t been fitted already if I’m being honest? So got lucky with that.
Barrie
I own 2 Mx5s, one a 94 Mk1 1840cc, the other a 2002 Sport.
Both have had K&N pads over 11 years, cleaned & serviced as book.
Both have been used over a (collective) 130,000 miles (ish) in all conditions.
Neither have given any bother in any way or have compromised any involved component.
I’ve been habitually fitting K&N filters to pretty much everything for nearly 30 years including a Courteney Turbo Opel Monza 3ltr, a Vulcan-Burton prepared Capri 2.8i to name but a couple. Never a day’s issue with K&N in any respect.