its said the be between 6-8 acording to a magazine review, but BHP is pub figures, chances are your clio wont be running above 168 BHP at the moment anyway. its all about the way the rs tuner changes the way the engine delivers the power, which is smoother, earlyer in the revs and all round more usable power. i got one when they were like £180 odd and after using it i would say they are worth £200 easy, but thats my opinion.
but forget BHP pub figures.