I prefer the Lucas Fuel Treatment ... I have noticed a mileage increase and smoother running engine (both my Bravada and RAM) when using the Lucas Treatment. I also use the Lucas Oil Treatment in both trucks ('00 Bravada has 125K on it - '02 RAM has 112K on it) and change oil 5-6K --- I personally know some guys that pull Super Pro Tractors and they went through engine bearings every 3-4 runs.... after using the Lucas products that problem is now GONE... Figure if this can fix that problem, it ain't gonna hurt my 2000 RPM engines :-)