My uncle did just recently put a kit version of this on his '01 S10. his kit came out of Canada but I don't exactly know where. he also had some white power that was mixed with the water. it claimed 30% increse... if you really think about it, on an EFI car, with little bit of HHO going into the engine, that will richen the mixture just a little and the 02 sensor will read that and lean the mixture accordingly, thus using less fuel