The EPA and the National Highway Traffic Safety Administration (NHTSA) are in the process of revising the fuel economy label that is required on all new cars and light-duty trucks sold in the U.S. Two prototypes — a horizontal and a vertical version — are the primary label designs under consideration.
Recently, Siegel + Gale, a leading strategic branding agency, completed user testing on both of the proposed label designs. Neither was perfect, but overall the horizontal label tested as more usable.

EPA Fuel Economy Labels