Prius plug-in displays battery of good points

0 Comments | USA TODAY, January, 2008 | by James R. Healey

DETROIT -- Seventy-one miles per gallon.

That's what the trip computer read after a 4-mile loop through downtown and a short freeway blast in a prototype of the Toyota Prius plug-in hybrid.

Skip the freeway run, go lighter on the throttle downtown and the reading could have been infinite, because the car would have stayed entirely on battery power, never tapping its gasoline engine for help.

The best of the current, regular hybrids -- the Prius non-plug-in variety -- has mileage ratings in the mid-40s.

How they differ:

*Regular hybrids blend the output of an electric motor and gasoline engine to save fuel. Their batteries are recharged when you slow or stop the car, a process called regenerative braking that turns the electric...