Gembam, who lives in the San Francisco suburb of Corte Madera, spent several months and about $3,000 to modify his Prius to allow the extra batteries to be recharged by plugging them into the grid. The extra batteries let Gremban drive for 20 miles with a 50-50 mix of gas and electricity. Even after the car runs out of the extra juice from the batteries and switches to the standard hybrid mode, it gets the typical Prius fuel efficiency of around 45 mpg. As long as Gremban doesn't drive too far in a day, he gets 80 mpg.While not quite at the 110 mpg level that we reported possible last week, Grembam's numbers come from his daily driving, and not the carefully controlled test conditions of the 110 mpg-ers. "The value of plug-in hybrids is they can dramatically reduce gasoline usage for the first few miles every day," Gremban said. "The average for people's usage of a car is somewhere around 30 to 40 miles per day. During that kind of driving, the plug-in hybrid can make a dramatic difference."
Though the technology is certainly available, when it comes to mass production for the consumer market, manufacturers are worried about the added cost of producing plug-in hybrids. Some in the private sector, like Gembam, and University of California-Davis engineering professor Andy Frank, aren't waiting. Frank first built a plug-in hybrid in 1972 and has since built seven others, one of which gets up to 250 mpg. They were all converted from non-hybrids, including a Ford Taurus and Chevy Suburban.
Frank has spent $150,000 to $250,000 in research costs on each car, but believes automakers could mass-produce them by adding just $6,000 to each vehicle's price tag. via ::AP