I have been reading some opinions over at Bob is the Oil Guy and apparently there are a LOT of folks that belive K&N air filters are the worst thing you can put on your vehicle. The speak of large amounts of engine damaging dust being sucked into the engine, ruined MAF sensors, accelerated engine wear, etc. Apparently the only evidence to support this claim was a test done back in 2004 by Arlen Spicer. http://www.dieselplace.com/forum/3-...rmarket-air-intakes-filters-do-they-work.html I've used K&N air filters for years with no problems. My thing is, if K&N air filters were so terrible, would not competing air filter makers test their air filters against K&N, publish tests to try to get people to buy their filters over K&N?