In the 1980's I drove a Cadillac with a digital MPG counter on the dashboard. It could be toggled to either display the average or the real-time fuel consumption. I keep thinking that if all vehicles had that, people could more easily conserve their fuel.
You probably all know or have met one of those fantasy league players who are so totally into their "team" and their "team"'s standings that they continually obsess about it. This could be even bigger than that. With the price of gas where it is, everyone wants better mileage. The display could even cause people to drive better. My ex-husband was always bugging me about "the rabbit starts" when I used the Caddy.
This article talks about real-time MPG as if it's some kind of new and revolutionary tech - probably because it's being applied remotely to a new electric prototype. Teh tech is old, and IMHO, should be on all cars now.