Instead of pressurizing the combustion chambers to within an inch of their life, they're aiming to squeeze as many miles as possible out of a gallon gas and whenever possible not even use the engine. To make this happen they're creating plug-in hybrids. Companies like CalCars and EnergyCS are converting production Priuses into plug-in hybrids. They're replacing the batteries with higher capacity units to allow the cars to run farther on battery alone. They're also adding the necessary wiring and control software to enable the cars to be plugged into a standard 110V outlet to charge at home. So far they claim to be achieving 100 mpg and a 50 mile range on the battery. They and other groups are also encouraging car-makers to create production PHEVs as GM committed to yesterday.