Can adding this to your car make it more fuel-efficient?

Blade by Sabertec promises to increase a car’s fuel efficiency and reduce the pollutants being released by the vehicle, and people don’t have to do anything but attach it to their car’s tailpipe. The premise sounds interesting and ridiculously simple you’d wonder why no one ever thought of developing such a product before. There’s a lively discussion over at Treehugger right now regarding the truth of this product’s claims. How do you weigh in on this issue? Can making cars more fuel-efficient really be as easy as this?