The stop/start system was supposed to also be on the new Rams a few years back. The EPA estimated mileage wasn't much better than without it. I know that the OEMs are turning over every stone they can to find improvements. The stop/start stuff worries me a bit because it adds complexity. Sure, a piston is still a piston but all the additional electronics in new cars makes it so a regular gearhead now has to resort to an actual professional to fix his car.