The fashionable economics of hybrid cars.

Last year, Dallas computer whiz Tony Scott drove a BMW M series, an expensive car that BMW advertises as "a race car for four." Then, contemplating the need for a new $1,200 set of Z-rated tires and a future of 15 miles a gallon on premium gas, he made a decision. He traded the Beemer for a Toyota Prius sedan, a car that gets attention for its mpg, not its mph. One month later he bought another one for his wife, relegating their diesel Ford Excursion to what he calls "recreational status."