Carmakers' plug-in plans

Chrysler Corp.'s Sprinter Plug-in is hard at work at the New York Times. It carries newspapers out of the paper's printing plant in the New York City borough of Queens.

The Sprinter Plug-in has a diesel engine. Diesel engines, on their own, are more fuel-efficient than gasoline engines and they have a lot of low-speed pulling power that makes them ideal for hauling.

After charging overnight at the plant, the Sprinter Plug-in can drive up to 20 miles on electricity alone. That's enough to complete a day's worth of short urban runs without using any gasoline at all.

Beyond that, the Sprinter Plug-in operates, like other hybrid vehicles, on its electric motors and internal combustion engines combined.

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