So far, the market for extended range electric vehicles in North America seems to be the exclusive province of General Motors, Chrysler and Fisker with Ford sticking to the parallel hybrid route - both with and without plugs. It's not that Ford hasn't investigated the concept of ER-EVs, they actually had a working example before GM did with the HySeries drive Edge in early 2007. For now, though, they are putting their focus elsewhere.
Nancy Gioia, the director of sustainable mobility technologies at Ford explained that her engineers didn't feel that an ER-EV (or series hybrid or whatever else you choose to call it) could provide the necessary sustained performance levels required for mainstream use. Because of the limitations of current battery density and the inability to predict what power demand might be five minutes down the road, the vehicle could end up in a situation where it has insufficient power. Toyota officials have cited the same issue with ER-EVs as reason for not going in that direction. GM clearly believes it has enough reserve power to meet the demands of the average driver with the Volt powertrain. We'll just have to wait and see.