If you get interested in reading some actual testing data, you could start with some people who really want find something that works so they can require us to buy it then tax it.
Gas Saving and Emission Reduction Devices Evaluation
http://www.epa.gov/otaq/consumer/reports.htm
I'm sure George Wiseman will provide you with the details of the 7000 mpg world record if you asked him. I think he is pretty busy providing customers with some real mpg improvements to put alot of stuff on his site. Here's another true story of college student competion where the winners achieved over 3000 mpg's. Before you call it a fraud please check it out. It's not made up. I'm sure if there technology were to be put on an average size car it would drop those numbers alot but at over 3000 it would still be incredible by car makers standards. I hope you can admitt that you are just simply misinformed on high mpg's inventions.http://www.drivers.com/article/898/