@graphiteghost , I was concerned about the figures and did some research on it awhile ago and emailed a few suppliers encluding rob from needs wings and he told me those figure from 5-10 hp with the mangaflow and have read other things I know there is little if any to gain with our cars , reason why I looked into it is because I got a after market muffler on my and it seemed to feel like I lost low end torque in first and second gear but as you said most likly even some little as 1 hp guess its a marketing thing to st least advertise that amount , I haven't found any dynos stock but exsaust yet... Do you have any links?