Road-Testing Cars of the Future

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That's a key lesson. Engineers at Honda and other automakers say that for new technology to catch on, familiarity is vital. A few buyers might be willing to learn new habits or accept trade-offs, but mainstream drivers just want to get in and go. The Clarity lets them. It holds four comfortably, with a big trunk, and has the luxury features of an Acura RL. It can travel up to 280 miles on a tank of hydrogen, at a cost per mile that's less than half that of gasoline. The fuel is even self-serve.

But the Clarity is still a costly experiment that's a long way from most highways. The drivers in Honda's test program pay about $600 a month to lease the Clarity, but that's a fraction of the car's real costs. That's because some of the fuel-cell components are still fairly exotic. "We need to reduce cost by a factor of 10, over 10 years," says Ben Knight, Honda's North American research and development chief. "That puts it into the range of conventional vehicles."

There are other problems. Hydrogen needs to be shipped and stored under pressure, which would require a new nationwide network of filling stations. There are a few hydrogen stations scattered around Southern California and other regions, but making the fuel widely available would probably require a massive program subsidized by the federal government. GM, Ford, Toyota, and other automakers have hydrogen programs too, and if the technology catches on, their combined might could sway Washington. But many politicians still favor the oil economy, and with Washington spending trillions of dollars to combat the recession, funding for other huge projects is likely to be scarce.

BMW Hydrogen 7. BMW's hydrogen strategy is different from Honda's. Instead of channeling hydrogen to a fuel cell, this modified 7-series sedan burns it in the same internal-combustion engine that burns gas. The car has two fuel tanks, two fuel doors, and two fuel gauges on the dash. There's a button on the steering wheel, labeled H2, that toggles between fuels when you push it, sending either hydrogen or gasoline into the cylinders. The dual setup entails lots of compromises, like reduced engine power and limited storage. And the Hydrogen 7 isn't perfectly clean; it emits trace amounts of nitrous oxide, enough to displease hard-core environmentalists.

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BMW points out that the Hydrogen 7, which is a demonstration car not available for sale or lease, is meant as a half-measure until hydrogen is widely available. Meanwhile, the car highlights a few adaptations that drivers will have to make. When the car is running on hydrogen, for instance, the trip computer expresses fuel economy as kilograms per 100 kilometers. In normal driving, the Hydrogen 7 averages about 3.5 kilograms per 100 kilometers—roughly 30 miles per gallon. Government regulators are still working on standardized ways to measure hydrogen, including fuel efficiency and even how to price it.

Chevrolet Volt. Will the electric car save GM? Will it run as advertised, without epic breakdowns? Will anybody even buy it? In 100 years of automotive history, there may never have been an unproven vehicle with so much riding on it. "If they pull it off, they will have leapfrogged Toyota," predicts William Holstein, author of the new book Why GM Matters.

Here's the scheme: Drivers will charge the Volt at home, from a regular outlet, like a laptop or cellphone. The car's lithium-ion battery will power the car for up to 40 miles without any gasoline or tailpipe emissions. If you need to drive farther, a small gas engine will power the motor, ensuring that drivers don't suffer from "range anxiety." GM says that charging the car at home will cost less than $1 per day and drain less energy than it takes to run a refrigerator.