how well you maintain them my azzzz. the one i bought new, was oiled. so about 12,000 miles later the rings are out of my engine--and 1 qt of oil every 15 miles--like mike said about the particles. but heres the kicker, it lets the smaller particles thru--and thats just like taking polishing compound to the rings in your engine--eats the rings right out, and doesnt seem to bother the pistons, because there forged, or the ford blocks, because they are hard--and i bet id have a lot of fun trying to sue those pukes. the idependent tests i read one time--said the k&n only flowed like 2% better. your engine worth that-----------N O T !!!!!!! ths was a unbiased test not paid for by k&n!!!!!!!!!!!