Ford did the right thing when it developed their EcoBoost engines. The EcoBoost is a collection of incremental improvements to their internal combustion engine, not a technological moonshot which is the Volt. The Volt certainly saves more gasoline than a car with an EcoBoost engine, but there are only a few thousand Volts on the road, and there are now millions of EcoBoost engines on the road.
A monumental increase in gasoline mileage COULD be achieved with the vehicles now in existence, without increasing the costs of new vehicles, in fact there would probably be a small DECREASE in the cost of new vehicles. I say in advance that it will never happen though because it is too simple, flies in the face of “accepted wisdom” and requires some effort by drivers.
What am I getting at? Simply that for maximum fuel economy drivers should be reeducated to STOP using cruise control and learn to drive for maximum mileage instead. Cruise control is a gas waster.