Does anyone have any data that shows that the K&N filter helps get any better mileage in the RX400h or Highlander? In my last two cars I had K&N filters and the claim was increased HP. But I also changed out the air filter housings for increased air low.

I would change out the filter (in the stock housing) if it helps, here is the http://www.knfilters.com/search/prod...x?Prod=33-2344