I currently use this on my truck and my wife's car. We have both noticed an mpg gain when we first used it. It is recommended to use the product every 4,000 miles to keep your fuel system clean. One of my customers driving a newer model Toyota Forerunner began using it along with the Signature Series Oil and he noticed a 1.5 mpg increase in his mileage. He commutes about 160 miles round trip each day, so he is pretty familiar with mileage on his vehicle. It is not going to dramatically increase mileage on a Power Wagon, but I did notice about a .5 mpg increase in city driving when I first added it. I did not have enough highway driving to compare numbers prior to adding it, but everyone I know who uses it seems to notice a slight increase in mileage. I would imagine the biggest gains would be realized by vehicles with engines that have more mileage and thus more buildup and deposits that need cleaning.
This is specifically for gas automobiles. They make a separate additive for small engines as well.
Feel free to check out the website to make and order.
Code4Synthetics.com
If you have questions, feel free to send me a message or give me a call.