The day after President Bush pleaded with Americans to "be prudent in their use of energy," Nestor Zabala pulled into a Baltimore gas station and ignored the commander in chief, topping off the tank of his Honda Accord.

His excuse? A leisurely Labor Day weekend drive to New York. "I've got tickets to Shakespeare in the Park," said the 34-year-old architect, as he pumped $5, then $10, then $15 into his car on Friday.

As government leaders and energy companies try to prevent a disruption in the nation's fuel supply from spiraling into a consumer crisis, they are discovering one immovable stumbling block: American culture.

In a country where rising incomes have spawned five-car families and sprawl has given rise to two-hour daily commutes, a full tank of regular unleaded gasoline is regarded as a birthright, and the automobile is considered an essential tool in the mobile economy.

In a pinch, consumers might skip a dinner out. But few will ever consider, let alone actually pass on, a tank of gas.

"We equate cheap gasoline with freedom," said Kevin Forbes, chairman of the business and economics department at Catholic University in Washington. "It's almost as if we as Americans believe we have a constitutional right to cheap energy."

Gas is life in the United States -- an unseen and for the most part little-fretted-over chain of carbons that lubricates the trip to the grocery store, the ride to school, the weekend getaway. It powers a dizzying array of toys and gadgets -- not only cars, but sleek cigarette boats and four-wheel drives and all-terrain vehicles and custom Harley choppers and Ski-Doos and Sea-Doos. We're not quite sure how, but like the sewer system or the interstate or the Internet, it's somehow always there.

Until it isn't. Like it wasn't last week at gas stations across the country, setting off a modest panic.

So despite strong arguments for restraint in the wake of Hurricane Katrina, Bush's seemingly reasonable request has fallen on deaf ears and full tanks. In some cases, it may even have encouraged the kind of gratuitous consumption the president had hoped to avoid, this being the home not only of car-ism but also of libertarianism.

Across the country, drivers far from Katrina's wrath didn't just fill up at the pump, they hoarded gas -- topping off tanks in Texas, filling up gallon cans in Maryland, even storing extra fuel in empty cooking-oil containers in North Carolina.

The trouble, for Bush and the rest of the country, is that rising gas prices and fears of a shortage have collided with deeply held convictions that consumers deserve fuel.

It is by no means a new notion. For a historical reference, see Carter, Jimmy, 1977.

After Carter called on Americans to conserve their way out of an energy crisis, voters booted the abstemious president out of office. The second-term Bush has no such worries, but it's telling that a man who could rally the country around a war cannot persuade the average driver to abstain at the pump.

"Don't buy gas if you don't need it," the president implored. But that logic was little match for the worry that settled over large swaths of the country, stoked by lines at the pump, sporadic gas shortages and wild rumors -- one of which convinced hundreds, if not thousands, of Maryland residents that gas stations would close for business at 4 p.m. Friday. (They did not.)

Drivers might feel guilty about filling up when they don't need to. But they still do it.

"I know it's the worst thing you can do," said Steve Gordon, a Baltimore liquor store owner who topped off his tank last week. "I didn't really need the gas."

At work, Fajid Tarar, who owns 15 gas stations in Maryland, instructs his employees to calm anxious consumers. (With good reason: Five of his stations went dry last week.)

But closer to home, Tarar is not taking any chances. "My wife is in Ocean City," said Tarar, who lives in Owings Mills. "I told her, 'Fill up your tank. For God's sake, everyone will run out of gas, and then what will you do?' "

If consumers can't give up a car, can't they at least conserve a little?

In the Washington region, the average vehicle gets 23.7 miles a gallon, slightly less than the national average, according to the Metropolitan Washington Council of Governments. That fuel use costs about $17.5 million daily.

People could drive less, by organizing trips more efficiently, carpooling or using the Metro. Or they could buy fuel-efficient vehicles.

They could do that, just as they could abstain from eating artery-clogging fast food. But this is America, the country of live free or die, the country where Henry Ford created the automobile revolution and where Hummers, which get about 12 miles per gallon, have become urban status symbols.

All of which is to say that the last thing American consumers want is to be told what not to consume.

"We don't like the government to tell us what to do," said Lars Perner, an assistant professor of marketing at San Diego State University who specializes in consumer psychology.

Perner argues on his Web site that as gas prices rise, consumers will reduce spending on a variety of products and services -- just not on gas. "In the United States," he writes, "it appears relatively difficult to reduce gasoline consumption."

For one thing, he notes, strong economic growth in the 1990s encouraged Americans to buy expensive, gas-guzzling cars. The ambition to drive a more fuel-efficient alternative might exist, but it would involve trading in that handsome, all-terrain SUV and "taking a loss" on its value, Perner said.

Gerald Smith, chairman of Boston College's marketing faculty, said consumers find it nearly impossible to break their addiction to gas because the possessions that depend on it -- primarily cars, but also boats, motorcycles and lawn mowers -- are "psychologically sticky."

"People are very averse to losses and to giving up use of something they already own," Smith said.

Ask Bernie Rothman, who needs gas to ride from New Jersey to the Eastern Shore -- in his 1,000-horsepower off-shore racing boat named Euphoric.

Just last weekend, Rothman put about $500 worth of gas into Euphoric. He didn't even ask his buddies to chip in, he said from the driver's seat of the boat, docked at Red Eye's Dock Bar on the Eastern Shore. "I have no control over the price of fuel," said Rothman, 35, owner of a tire and auto repair center in New Jersey.

Maybe he won't go as far this weekend, he said, and maybe he won't go as fast. But he's still going.

Washington Post staff writer Justin Gillis contributed to this report.

Drivers wait to buy gasoline at a Northwest Washington station at Georgia Avenue and Piney Branch Road.