Reuters: Pricey gasoline drives US car buyers to more fuel-efficient vehicles, according to a study by industry tracking service Edmunds.com released Wednesday. Shoppers looking at cars and light trucks become more sensitive when prices rise above an average national price of US$2.80 a gallon, according to Edmunds.com Executive Director David Tompkins, who called that level a “psychological turning point for consumers.” The average US retail price for gasoline stands at …