Driven by concerns over global warming and the prospect of tougher restrictions, automakers worldwide have moved up a gear in the race to build the ultimate clean car.
Japanese firms enjoyed success in energy efficiency and low nitrogen oxide emissions in the 1970s and 1980s, but the ongoing competition represents a fundamentally new ball game -- a shift from gasoline to cleaner energy sources.
With your current subscription plan you can comment on stories. However, before writing your first comment, please create a display name in the Profile section of your subscriber account page.