After using your product in our vehicles it has increased the milage greatly. At christmas in 2006 I got 36 miles to the gallon in the intrepid also there was a flutter that I noticed on the Tac when it had been idiling for awhile, this has gone away, also on some trips to Calgary Alberta I have been getting 31 to 34 miles per gallon,with the Astro van and have noticed a much better engine performance and also saving money on fuel wich has been on a average over a dollar per liter this last year. Don York