I know from the motorcycle side that K&N filters arn't allowed to flow any more air than standard filters, i would think the only advatage would be by fitting an induction kit and doing away with the air box but you then have the issue of noise. I stand to be corrected on this but i know they don't make any difference with bikes and you need to look at different manufactuers if you want increased air flow. If only Carlsberg made air filtetrs