Why We Keep Pumping Gas, Not Greener Fuels

Who needs oil?

That's clearly going to be the theme among automakers this year as they compete for the green spotlight. General Motors has announced an investment in a company that claims it can make ethanol from garbage and old tires, at half the cost of gasoline. Honda plans to begin leasing a vehicle this summer that's powered by hydrogen. Hybrids will come in more flavors than ever, and you might start to feel like a dinosaur if you don't know what a ZEV is. (It's a zero-emissions vehicle.)

But don't sell your Exxon stock. For all the hype—and the very good reasons to seek alternative fuels—gasoline will still power the vast majority of cars five years from now, and probably 10. True, some alternatives look very promising. Cellulosic ethanol, the kind GM is backing, can be made without imported hydrocarbons, and it generates a lot more energy than is required to produce it. Electric cars could be charged at home for less than gasoline costs. Hydrogen, if ever mass-produced, could be a miracle fuel that provides great mileage with zero emissions.

But so far, every alternative to carbon-based fuel comes with trade-offs that reveal the reasons we're so addicted to gasoline in the first place:

It's cheap. Sure, $3 gas might seem expensive—compared with the heady days when it was barely a buck a gallon. But mile for mile, virtually nothing is cheaper. Corn ethanol has been around for a while, for instance but hasn't caught on because it yields lower mileage and ends up costing drivers more. Diesel fuel offers great performance in cars, but the engines and new technology needed to trap pollutants make the vehicles more expensive. Hybrids save money over time, through lower gas bills, but it takes years to recoup the $2,000 to $4,000 premium. And new kinds of fuels will require vast new infrastructure that will surely add to the cost. Some may end up cheaper than gasoline, but it might take $4 or even $5 gas to tip the scales.

It's efficient. Diesel, cellulosic ethanol, and hydrogen pack more energy per pound than gasoline. Hydrogen and electric-powered vehicles would pollute less. But gasoline gets a B in both areas: Gas-powered cars perform well, and modern filters can greatly reduce tailpipe emissions without crippling performance. At current prices, that's a winning combo for most consumers.

It's here. The distribution challenges associated with other fuels illustrate how convenient it is to have a gas station on every corner. Many Americans would have to drive hundreds or thousands of miles to find an ethanol pump. GM has confined a real-world test of 100 fuel-cell cars to just a couple of cities on the East and West coasts—because they're among the few places where you can get hydrogen fuel. One thing that might be more convenient than filling up at the local gas station would be plugging an electric car into an outlet at home. But so far, there are no mass-produced batteries that would work in such a car. And getting most new fuels to consumers would require new infrastructure costing billions.

It's simple. A lot of technology in the works would involve more than one power source in the car—an electric motor, for instance, that's powered by a battery, which is charged by a gas engine (a conventional hybrid), a fuel-cell stack (hydrogen), or power from the electrical grid (a plug-in hybrid). All such systems would raise mileage, cut oil consumption, and lower pollution, but multiple systems also add to costs and complexity. Gas engines do it all with one power source and one fuel.

Nobody has come up with anything better. After years of talk about 100-mpg cars and the need for energy independence, big companies and wealthy investors are finally putting real money into alternative fuels—the biggest factor in determining whether they ever get mass-produced. But gasoline sets a high bar. Thousands of scientists are working on clean, cheap ways to power a car without burning oil, sending dollars overseas, or inconveniencing consumers. When they figure it out, a revolution will ensue. But along the way, we're learning that gasoline is a tough act to follow.