Just as storms sank the massive Spanish Armada four centuries ago, the executives at Nissan must worry that Katrina, or at least the high gas prices that followed it, will swamp their own Armada, a 9,600-pound SUV that gets 13 miles per galleon, er, gallon. Not just the Armada: the Associated Press this week reported that sales of SUVs such as the GMC Envoy and Chevrolet Tahoe were off 50 percent, while sales of the Cadillac Escalade, Ford Explorer, Toyota Sequoia and the Armada were off by at least 18 percent. Anyone want to talk about improved fuel-economy standards?

Of course not, or you would have bought a gas-electric hybrid years ago. In any event, gas prices were only part of the reason for the dismal sales in September for the oversize-car industry: It just spent the summer cutting prices to lure buyers and anyone who wanted to but would have done so by late August. But maybe with thousands of Americans perched in brand-new vehicles that get lousy mileage, now is the best time to talk about encouraging more efficient use of an increasingly scarce fuel. Two interesting ideas have been tossed around recently.

The first comes from New York Times columnist John Tierney, and all those new SUV drivers will hate it. Mr. Tierney tips his hand by calling it a modest proposal, but his plan, he claims, will “fight global warming, save energy, cut air pollution, ease traffic congestion, reduce highway fatalities and, while we’re at it, reform Social Security.” He would add 50 cents per gallon to the gas tax, then refund that money through private Social Security accounts, which would keep the tax revenue neutral while providing a fanciful way of attracting conservatives to support a tax increase.

He quotes, surprisingly, the nation’s leading anti-taxer Grover Norquist saying that if it fit in to an overall tax reduction package, “it wouldn’t violate the no-tax pledge.” A 50-cent gas tax, says Mr. Tierney, will maintain the incentive to drive less once the price of gas drops, which will reduce both road congestion and pollution, while being close to the figure one study suggests is needed to compensate for the costs (roads, pollution) drivers impose on society.

The second idea comes from Sen. Barack Obama of Illinois, who is looking for a way to make car and truck fuel-economy standards something less than the dead end they have been for more than a decade. To do that, he must overcome objections within his own Democratic Party – specifically, Sen. Carl Levin of Michigan, who more than any other member of Congress has ensured industry fuel economy here will be among the worst in the world. Sen. Obama’s solution is simple: He would have the government bribe Detroit.

He doesn’t put like that exactly: He first laments the auto industry’s high retiree costs, than says, “By picking up part of the tab for the health care costs of their retirees, we’d be lifting a huge burden off the auto industry so that they’ll invest in the technology that will finally reduce America’s dependence of foreign oil.”

While both these ideas are attempts to buy the allegiance of groups that otherwise would resist reform, the public should support anyone trying new approaches to solve what has become a problem not of technology but politics. Mr. Tierney will need to do better than Social Security accounts to attract congressional support and Sen. Obama might be a little less generous with tax dollars to the auto industry, but the new approaches are welcome. The public needs more such ideas for getting off its gasoline addiction.