The new regulations still mean that hundreds of cars on the market today would be illegal in 2020. So cars will have to change to achieve a one-quarter boost in fuel economy. Hybrids, which now make up a little more than 2 percent of the new car market, will become much more mainstream--the Prius already ranks among the top 10 vehicles sold in America. Electric cars also will get new life. Already the race is on among major automakers to develop a lithium-ion battery, like those found in laptops, that can power a car for up to 100 miles on a single charge and then juice up again in as little as an hour. General Motors has the Chevy Volt plug-in electric, which has a small motor to recharge the battery after 40 miles, coming in 2010. Toyota will be showing off a plug-in Prius prototype at the Detroit Auto Show next month. And Nissan CEO Carlos Ghosn promises to have a small electric city car on the road by 2011. "I'm convinced that for urban driving, the answer will be the electric vehicle," Ghosn recently told me. "With oil at $100 a barrel, there's a lot of interest in a zero-emission electric car."

Cars will also get smaller. Not clown-car small, and probably not even sleek European small--just trimmer and much lighter, thanks to more use of aluminum and lightweight composite materials that save on gas but cost a lot of dough. Good old internal-combustion engines will also get smaller and a lot more efficient in how they burn gas. (Yes, we'll still be guzzling gas in 2020, just less of it.) To cover the cost of going the extra mile, sticker prices will go up, by a few hundred dollars if you believe the environmentalists and by thousands if you believe the automakers. The reality will be somewhere in between.

But fear not, you will still be able to get big rigs in 2020. In some cases, those models will not be as big as they once were and won't have four-wheel drive, but this legislation will not be the death of the SUV. Old-school SUVs built on pickup truck frames might become endangered, but the new lighter crossover utility vehicles, like the Honda Pilot, are probably here to stay. And we wouldn't have it any other way. Consider this: even with gas stubbornly above $3 a gallon this year, sales of large and luxury SUVs are up 5.6 percent.

"I don't think Americans have yet been weaned off the 'bigger is better' way of thinking," says Edmunds. "We're a country of wide open spaces and a sense of scale appeals to us. Besides, people feel safer in bigger vehicles. And safety outweighs fuel economy for many people."

So what's the biggest difference we'll notice on the roads in 2020? Cars will look much sleeker. The cheapest way for automakers to jack up mileage is to design highly aerodynamic cars that slip through the wind. That means lower hoods, smoother shapes and maybe even covered wheels. But they still won't fly. Sorry, George.

© 2007