Temple University physics professor Rongjia Tao has developed a simple device that could dramatically improve fuel efficiency in automobiles by as much as 20 percent.

The device attaches to the fuel line of a car's engine near the fuel injector.

Six months of road testing in a diesel-powered Mercedes-Benz automobile showed an increase from 32 miles per gallon to 38 mpg, a 20 percent boost, and a 12-15 percent gain in city driving.

Link: http://www.temple.edu/newsroom/2008_2009/09/stories/taofueldevice.htm