^^^ Great test. I was trying to repeat it for E39M5 filters a few years ago- was going to pass the hat over on another forum to get the question answered.... jsut ran out of interest.

Some one did do a dyno with and without a filter. About 2% (8hp) difference on a 400 HP motor. So do the math on what you can expect with a 'better' filter.

Really interesting to read how many parameters come into play when specing a filter..and how woefully inadequate the K&N test data are that they 'publish'.

I recommend replacing the factory filter at 2X the recommented interval- you'll avoid running with a partially clogged filter for 50% of your miles! Easy

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