Bob G,

Thanks for the info. I may go with the Powerchip. I have K&N filters, and although I think I feel a difference, it may be wishful thinking. K&N claims a 2-4% increase in power, so I assume that really means 2%. If they overestimate their increases to the same extent that Powerchip does, then than means 1%, or 1.75 horsepower increase at the rear wheels. Between the two, that's probably an increase of 10-11 hp, and that's worthwhile.