http://www.wired.com/autopia/2011/01/measuring-the-impact-of-instant-mpg-info
"Chuck Squatriglia, Wired Magazine" said:
Although some studies have shown that next-gen dashboard displays make us more-efficient drivers, none of them has created a baseline of driver behavior from which to truly compare the changes. Researchers at University of California campuses at Berkeley, Riverside and Davis have launched a study to do just that. They want to see how much drivers change their behavior in the face of instant feedback on the efficiency of their driving habits.