Fuel Economy

President Obama's threat to cut off government loans and bring on bankruptcy has given him unprecedented leverage to realize his vision of Detroit as the world leader in greener cars. Yet even if the president succeeds in getting domestic carmakers onto firmer financial ground, even if Detroit overcomes decades of consumer skepticism about the quality of its products and begins cranking out fuel-efficient cars that don't damage the environment -- even then the U.S. auto industry could die.

The road to recovery for U.S. automakers could be jammed with hundreds of thousands of gas-guzzling used cars, which President Obama hopes will be traded in for more fuel-efficient vehicles -- with the lure of government money. So-called cash-for-clunkers programs in Germany and France have worked well this year to spur new car sales. But similar initiatives aimed at reducing smog in Southern California have not fared so well in recent years.

Say you buy a car that coughs out a lot of greenhouse gases. Should you pay more for the privilege of polluting? And say your neighbor buys a car that spews out far less. Should he be rewarded for helping to save the planet? This week, the California Assembly is expected to vote on the California Clean Car Discount Act, which, if passed, would be the nation's first "feebate" law, imposing charges and granting rebates based on a vehicle's emission of carbon dioxide and other gases.

William Lowry recently spent $500 to replace the tires on his Toyota Camry hybrid. The salesman said the Goodyear Regatta 2 tires were just as good as the Bridgestone Turanzas that came with the car. But it didn't take long for Lowry to notice that his fuel economy had fallen by five miles a gallon. "I would have paid more for tires that get better mileage.

Not everything you've heard about increasing gas mileage is true. There are plenty of legitimate ways to stretch your mileage: slow down, keep tires at proper inflation, avoid quick acceleration, don't pile luggage on a roof rack, use a properly fitted gas cap. But at this time of skyrocketing gasoline prices, several myths are circulating. The claims were tested by car experts at the Automobile Club of Southern California and Consumer Reports magazine.

A month of gasoline prices near $4 a gallon was enough to sour Americans' long love affair with trucks and sport utility vehicles, pushing them back into sedans -- and driving Detroit's automakers into deeper trouble. U.S. sales results released Tuesday showed cars outselling gas-guzzling trucks and SUVs by almost 200,000 in May -- the biggest margin since 1996. That was bad news for U.S.

Faced with record-high oil prices, the world's leading economies and oil consumers Sunday pledged greater investment in energy efficiency and green technologies to control their spiraling thirst for petroleum. In a joint statement, energy ministers from the Group of Eight countries, joined by China, India and South Korea, also urged oil producers to boost output, which has stalled at about 85 million barrels a day since 2005, and called for cooperation between buyers and producers.

Henry Ford II was famous for saying "Big cars, big profits. Small cars, small profits." Now a better mantra for the country's second-largest carmaker might be "Big cars, no profits." Faced with crashing sales of big sport utility vehicles and pickups and an increasingly dim financial outlook as a result, Ford Motor Co.

Hybrids may be tops when it comes to saving gasoline, but they're far from the best choice for budget-conscious car buyers, a new study says. The four-door hatchback Chevy Aveo from General Motors Corp. leads the ranking of the best new-car values in terms of "total ownership cost" as calculated by automotive data firm Edmunds.com, based on $5-a-gallon gas. The highest-ranked hybrid was the Honda Civic at No. 10. The Toyota Prius hybrid -- No.

David Sikorski went to a Hertz in Austin, Texas, last month to rent a car for a business trip to Dallas. He'd booked a fuel-efficient mid-size sedan, hoping to keep expenses down on the 400-mile round trip. What he got was a 16-mile-per-gallon Ford Explorer sport utility vehicle. "I walked right back in and asked for something smaller," said the Austin computer data specialist, who eventually was given a Hyundai.