If you do a lot of research on this, there are a number of people (experts?) that claim that these products not only do NOT work, but they are cheaply made and in many instances have broken and the broken parts were sucked into the engine causing major damage. At one point, there was someone on ebay, that was in violation of their rules but ran a very very long "announcement", almost a dissertation proving that these tornados are detrimental to your car. He went on, and on, and on.... Anyway, since he was not selling anything, I'm sure he only lasted for a short time on ebay, but his "announcement" was as convincing as the late nite guys on TV that are pushing tornados. So if you do this, do your research first.