Another concept to extend fuel effiency is to produce a battery/gas hybrid vehicle. Such vehicles are already on the market, the Toyota Prius being the best example (why weren't american companies the first to figure out hybrids?). Some people have modified their cars to have more batteries and be plug-in rechargable at night; this allows for about 20-40 miles at a high fuel effiency (80 mpg), provided you plug in every night. Seems like a good deal for daily commuting. And after 20 miles, you would get about 44 mpg which is the typical Prius highway effiency. Seems like a good idea!

Of course the car mfrs are fighting this idea; claiming that people are too stupid to figure out that some cars should be plugged in, and some don't have to. Further they think that the public is not willing to go through the hassle of plugging in. If i were to save $10-$20 a week by plugging in, i would do it readily, assuming I actually had a place i could plug my car in (I don't right now).