I'm using it in my ramcharger, 318 TBI. I have only used 20 gals of fuel so far. But it has smoothed the idle and running of the motor. The xhaust smells much better also. I think Some of the people use to much or not enuff. I use 2 oz per 10 gals. of gas. On yahoo search I found some articles stating it helps for a more complete burn of the fuel. Does it, who knows. On RCC, some guy's have used it for a while have seen noticeable improvements.