3 Accord generations ago, Honda offered a hybrid powertrain in its mainstream sedan. But it was a performance-oriented V-6 hybrid that never achieved the lofty fuel-economy numbers that eco buyers crave. Now, Honda is jumping back into the game with a new, efficiency-oriented Accord hybrid, and its mileage is impressive. It’s rated by the EPA at 47 in the city and 46 on the highway. Moreover, it’s a plug-in hybrid, and when operating on electric power, it gets 124 mpge in the city and 105 on t