I've installed one in back in 99 w/ my accord 4cy. I noticed that it picked up a go power instantly after the installation. I realized that MPG didn't changed much until my 3rd fill up. I've increased it from avg 25 per gallon to 28 per gallon.. Ever since then, I am a true believer of Tornado. I've been recommended to all my friends and family. They all happy with my suggestions. Just wait 2-3 fill ups to pleasantly surprised with increased MPG...