Giant chrome and steel cars, polished high to glint proudly in the sun, once glided across America's superhighways, guzzling gasoline as if there was no tomorrow, ferrying Americans back and forth from their over-heated homes.

They were glorious floating sofas made without regard for the environment or economic efficiency and their era came to a crashing halt when the Organisation of Petroleum Exporting Countries (Opec) decided to use oil as a weapon just after the start of the Yom Kippur war.

The Arab oil embargo of 1973 -- actually a cut in supplies-- plunged a nation where the car was king into despair and self-doubt. It found it could no longer afford to consume cheap gasoline with carefree abandon and gobble up finite natural resources. "The party's over," declared philosopher EF Schumacher, who popularised the idea that "small isbeautiful."

Thus was born an era of environmental concern -- in the fuming and fretting of drivers forced to wait in long lines to buy gas, an event that produced a sort of collective nervous breakdown for motorists.

Americans traded horror stories and sharp rebukes in the queues. But the worst was yet to come -- the embargo triggered a series of sharp price increases that played havoc with the US and world economies, sending interest rates and inflation soaring.

Hazy memory:

Now 25 years later -- it all seems like a hazy memory, a distant bad dream. A new, although more efficient breed of gas guzzler roams the roadways -- the Sport Utility Vehicle -- and petrol prices are as low as they ever were and supplies plentiful.

Instead of worrying about whether they will run out of energy supplies, Americans worry instead over whether the stock market is heading for a crash. Every era, it seems, has its fear of the moment that brushes aside other memories.

The veteran British newsman HaroldEvans, in his new book, "The American Century," called the oil embargo a watershed event that along with runaway prices, a devalued dollar and a series of foreign rebuffs led Americans to question the future of their prosperity.

"The American century seemed to be collapsing," he wrote of those times. It is a thought few people indulge in 25 years later.

The oil embargo, which lasted from October 1973 to March 1974, inspired heated rhetoric, a debate on U.S. Foreign policy and a host of solutions with many of them falling by the wayside after oil prices collapsed in the 1980s.

The United States toyed with price controls and reduced the speed on highways to conserve fuel. Thermostats in homes and offices were dramatically lowered.

President Jimmy Carter, faced with a rapid bout of Opec price increases in 1977, donned a sweater to address the nation on the need to conserve fuel, declaring the energy crisis to be the "moral equivalent of war."

"(The oil embargo) was a wake up call to Americans," saidHenry Weigel, special assistant to the director of the Office of Energy Markets at the Energy Information Administration, a government agency.

The good old days:

"Up to that time no one worried about energy -- where it was coming from or how much it would cost and the embargo forced us to give that serious consideration," he said.

Congress mandated that cars get an average of 27.5 miles to the gallon and light trucks about -- far better than the eight to 14 miles to the gallon of the gas guzzler. The new standards helped the sale of Japanese imports and that in turn forced the American auto industry to reinvent its product.

The standards were met as cars everywhere became more efficient, burning cleaner fuels and polluting the environment less than they once did.

But as petrol prices dwindled, Americans forgot the crisis and forgot the threat that Opec once posed to their freewheeling lifestyle, although a key reason for the Gulf War in 1991 was to prevent Iraq's president Saddam Husseingrabbing more control of world oil supplies. The need for oil, probably more than other reason, liberated Kuwait. "We (the United States) are only five per cent of the world population and yet we use between 25 to 30 per cent of world oil production. The average American uses about 25 barrels of oil a year and we will have severe shortages if the rest of the world catches up with us," said Iraj Ershaghi, director of the Petroleum Engineering Programme at the University of Southern California in Los Angeles.

He cites studies that predict severe energy shortages in the 21st century. Oil production will probably peak by 2010, he says, and then decline to the point where, "we will again become aware of the exhaustibility of this resource."

Hill Huntington, the director of the Energy Modelling Forum at Stanford University in Palo Alto, California, warns that an Opec-style embargo can happen again.

"It is an issue that isn't discussed much these days, but it can happen again...I can easily see a situationwhere if there was a disruption in the Middle East, the economy could not adapt and something could snowball and return the world to sharp price increases," he said.