Honda calls it the Ecological Drive Assist System (EDAS).
It will stomp its little feet and turn blue if you are mean and use a heavy foot, but turn a nice ecological shade of green if you drive nicely.
TreeHugger has noted before how effective these fuel economy feedback systems can be; James Cascio noted "the Prius effect" a few years ago:
"One important reason why hybrid cars result in better mileage is that drivers suddenly have an indication of how various aspects of their driving habits shape mileage. Hybrid mailing lists are filled with people taking about "driver break-in periods" as new drivers, given immediate feedback from the car, learn how to drive in a mileage-optimal fashion. Most hybrid drivers see a steady improvement in mileage over the first year because of this."
But people don't need complicated gauges, in fact if they are driving they shouldn't have them. It's too much information when you simply need feedback. And Ford's silly growing leaves and vines is just annoying.
Like the ambient orb that provided feedback on energy use. Just give people what they need. Congratulations to Honda for getting this.
More Feedback Loops on TreeHugger
We Want Fuel Economy Feedback in All Cars
ECO Pedal by Nissan: Tactile Feedback in Gas Pedal to Help you Save Gas
New High-Tech Ford Hybrid Instrument Cluster 'Rewards' You for Efficient Driving