With Ford's hydrogen-powered hybrid, the Hy-Series, you could get 80 miles per gallon. Or its equivalent, factoring in the energy that goes into charging the other half of the powertrain, a lithium-ion powerpack. Here's how it works--and work it does, based on a recent brief test drive of this experimental vehicle.

The Hy-Series is plugged into 110 or 220 volts of household electricity to charge between trips. When you start out, it runs off battery power and an electric motor for the first 25 miles. Then it switches to the hydrogen fuel cell onboard that creates electricity the rest of the way, covering up to a total of 225 miles on the initial battery charge and a full tank of compressed hydrogen available at your nearest hydrogen filling station.

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The Hy-Series is based on a Ford Edge crossover vehicle. In my test drive, the car started, ran, and accelerated capably and quietly. We were trailed by a Ford chase car all the way--not because of concerns somebody would rear-end us and create Hindenberg II, since the torpedo-shaped carbon fiber tank is well sealed, and anyway, hydrogen vents upward, unlike gasoline, which puddles. The real reason was Ford only has a handful of Hy-Series prototypes and doesn't want them damaged by errant motorists trying to get a closer look.

The 80-mpg gasoline equivalent is based on a 50-mile daily commute, where the first 25 miles would be using battery power and the cost of electricity would be at about 10 cents a kilowatt hour. While a hydrogen Hy-Series for consumers might be a long way off, Ford says it could swap in a small gasoline or diesel engine for the hydrogen fuel cell and have a marketable vehicle in a couple years, provided the cost of lithium-ion battery packs comes down.