American drivers want better mileage—now!—and for the time being, there are only a few ways to accomplish that: smaller cars, smaller engines, and hybrids that use battery power to help improve the efficiency of an ordinary gas engine.
Within a few years, there may be more ways to cut gas bills, including better hybrids, electric cars charged from a household outlet, and ethanol made from cheap, ordinary plant materials. But many experts think the ultimate solution to America's fossil fuel addiction will be hydrogen. It's plentiful, packs three times the energy density of gasoline, and could end up much cheaper than gas. Hydrogen emits virtually no pollutants when burned. And we don't have to deal with dubious monarchies in the Middle East to get it. Gotta love that.
Even though it could be a decade or more before hydrogen technology becomes mainstream and fueling stations get built, every big automaker is investing heavily. Honda just started leasing the hydrogen-powered Clarity sedan to a few celebrities and other customers in Southern California. General Motors has been testing a fleet of about 100 hydrogen-powered SUVs by letting ordinary people drive them around under real-world conditions. Toyota and Ford both have their own prototypes.
I spent a few days recently driving BMW's entry in the hydrogen derby, a 7-series sedan able to run on either hydrogen or gasoline. The Hydrogen 7 isn't for sale yet, but BMW says it will be if a network of fueling stations ever materializes. Until then, here's what it's like to drive the car of the future:
It mimics today's cars... There's plenty of innovation under the hood, but the driving experience is nearly the same as with the cars we're already used to. Automakers understand that to persuade consumers to spend money on newfangled engines and other breakthrough technology, the car itself needs to be familiar and unthreatening. The Toyota Prius hybrid, for instance, looks podlike and strange, but the car's steering, braking, acceleration, and even its cupholders are very conventional. The same holds for the Hydrogen 7: It handles just like any other 7 series. And all the knobs and buttons—including the computerized iDrive dial—are exactly where BMW aficionados would expect them to be.
...With a few intriguing differences. A few noticeable oddities on the Hydrogen 7 stem from the fact that it's tuned to run on either gasoline or hydrogen. Two fuel tanks, for instance, take up extra space. The hydrogen tank sits between the rear seat and the trunk and cuts trunk space nearly in half. There are two fuel gauges, one for each tank. Two fuel doors also, since refueling is different for each. And on the steering wheel, there's a button that says H2, which toggles between fuels when you push it, sending either hydrogen or gasoline into the cylinders (but never both at the same time).
To ensure that driving characteristics are the same with either fuel, BMW also had to tune down the roaring V-12 engine to accommodate the hydrogen. The net result: Instead of the usual 438 horsepower, the modified dual-fuel V-12 produces only 265 horsepower. (It's enough, trust me.) This "dual mode" setup is a way to take advantage of emission-free hydrogen—if you can get it—while making sure you'll always be able to run on gas when no hydrogen is available. But that's just a bridge to the optimal configuration, which is a car that runs purely on hydrogen and requires no trade-offs or redundancies.
Kilograms per what? The Hydrogen 7 has one of those onboard computers that display your fuel efficiency—for both gasoline and hydrogen. Gas mileage, of course, is measured in the familiar mpg. But hydrogen mileage is flipped around and expressed in kilograms per 100 kilometers. This took a bit of noodling to understand, like figuring out the inverse of a currency exchange in a foreign country. Simply put, it's the metric version of how many gallons it takes to go 100 miles. If you're averaging 4 gallons per 100 miles, for instance, that's the same as 25 miles per gallon; 3 gallons per 100 miles would be 33 mpg. So in hydrogen terms, the lower the number, the better.
I started out averaging 3.3 kilograms of hydrogen per 100 kilometers. I tried to drive gently and see if I could improve on that, and I got it down to 2.9 for a while. Then I hit traffic, and it went back up to 3.2. I studied the instant efficiency reading, too, which ranged from 0 to 10. When coasting at about 50 miles per hour—a very efficient speed for most cars—my hydrogen consumption was less than 2 kilograms. But when pressing hard on the accelerator to pass somebody, I pegged the meter, burning the maximum 10 kilograms (or more).
If hydrogen catches on, there will have to be standardized metrics for expressing fuel economy. My guess is that the federal government will adopt something similar to the mpg construct, while taking account of the fact that hydrogen is typically measured by weight, not volume. So an Americanized version might be expressed as miles per pound. If that were the case, my 3.3 kilograms per 100 kilometers would equate to about 8.5 miles per pound of hydrogen. I think. Or maybe we'll just have to join the rest of the world and learn the metric system.
A mystifying engine compartment. As on most modern cars, the engine compartment in the Hydrogen 7 is more or less hermetically sealed, and I couldn't tell what was going on in there. But BMW's hydrogen technology is quite different from that being developed by most other automakers. Instead of a hydrogen-powered fuel-cell stack, which generates energy from chemistry rather than combustion, the Hydrogen 7 relies on the good ol' internal-combustion engine that's been around for more than a century. The cylinders simply burn hydrogen instead of gasoline. That still requires sophisticated technology, but what seems important is that the best engineering minds in the business are following different pathways toward the same general outcome: a viable alternative to fossil fuels. The broader the experiment, the more likely it is that there will be breakthroughs.
The futurecar seems a long way off. Over the course of a few days, the Hydrogen 7 ran smoothly, and it was fun driving a cutting-edge car. I got plenty of inquiries from people who saw the "clean energy" and "hydrogen" labels plastered all over the chassis and wanted to know when they might be able to get one. The doleful answer: no time soon. The biggest problem (for those who haven't picked up on it yet) is the lack of fueling stations.
If I had wanted to refuel the Hydrogen 7 myself, I couldn't have. BMW has its own mobile refueling system mounted on a truck, and that's the only way to refill the Hydrogen 7. There are a few other hydrogen stations scattered on the East and West coasts, but so far the automakers have different methods for transferring hydrogen to the car and storing it on board. Government and industry leaders might get with the program sometime soon and start developing a hydrogen plan. But they might also simply keep talking about energy independence while doing little about it. Which means the Hydrogen 7 might turn out to be a breakthrough car—or end up as a museum relic.