You would have to pry the keys of Allen Shepherd's 317-horsepower, 5.6-liter, V-8 Nissan Armada from his cold, dead hands. But even this S.U.V. stalwart knows he is fighting a rearguard action against the powerful rise of gasoline prices.

The owner of a home-health service in Clinton, Oklahoma, Shepherd switched to a more fuel-efficient model when he recently leased new cars for his employees. "I would say the decision was about 79 to 80 percent based on gas mileage," he says.

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Across the country, drivers who once flocked to Hummers, Suburbans, and heavy trucks are facing up to the grim reality of expensive gasoline. Prices have risen nearly 40 percent, to $4 a gallon in many places, and may remain elevated for some time to come. Some drivers, like Shepherd, are holding out where they can. But, after years of resisting compacts and other small cars, complaining they were too low to the ground, perhaps less safe, and lacking the heft to tote what might need toting, many vehicle buyers have surrendered, giving up the keys to the Tahoe or the Grand Cherokee and embracing the smallest of the small—the fewer cylinders the better.

"People are panicking" because of high gas prices, says Paul Mitchell, sales manager for Orlando Hyundai. "I've tripled my Accent sales."

"The small cars—the Accents and the Elantras—are just flying off the lot, while even six months ago people were still buying S.U.V.'s and full-size sedans," he says. "You don't need to be Sherlock Holmes to figure out what's going on."

It's easy to see why. Marlaina Napoli, a Connecticut teacher, says driving her big-block G.M.C. Envoy was costing her about $70 every five days. Last week, she bought a four-cylinder Nissan Altima, saying that gas mileage "was the No. 1 [reason] for buying a car."

Her fellow teacher, Tanya Mastoloni, went a step further, buying a 49cc scooter to replace her Audi Allroad Wagon. "It goes about 150 miles on one gallon of gas," she says, noting that the scooter has given her an added benefit: "I cut my commute in half because now I can take the back roads."
 
Last month, Kelley Blue Book Marketing Research found that higher gasoline prices are a strong consideration for nearly 60 percent of vehicle shoppers, an 11-point increase from the previous month. 

Compact cars now account for 35.6 percent of total new vehicle sales in the U.S. through April, compared with 26.5 percent in 2004, according to J.D. Power & Associates. Sales of large vehicles have slipped to about 24.4 percent of the total from just over 28.4 percent in the same time frame. Also, the number of four-cylinder cars sold has now risen above 40 percent, outstripping sales of both eight- and six-cylinder cars for the first time in years.

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