for the TRD Supercharger. It is really one great kit. It performs well and should be close to as reliable as stock. The mileage for me increased from 19 mpg on the freeway to 21 mpg, but city driving took a small hit (I can't keep my foot out of it.) I would say that with mixed driving I see about a 2 mpg reduction. If you're serious about it I would say do it. This thing is a blast to drive on a daily basis. Not to mention the funny looks you get from others when they hear this thing whine a bit.
