An analysis indicates that the fuel efficiency of vehicles purchased by consumers in the United States set a new record in the first half of this year. It attributed the shift to automakers’ offering a wider variety of models with good fuel performance, and to shoppers’ reacting to higher gasoline prices by choosing smaller models.
The study was conducted for the Natural Resources Defense Council, an environmental group that favors stricter gas mileage standards.
The analysis, by Baum & Associates of West Bloomfield, Mich., calculated that fuel economy reached 23.8 miles per gallon, up 1.1 mile from the first six months of 2011. The study relied on fuel economy data from the University of Michigan and sales data from Ward’s Automotive.
Gasoline prices rose steadily from December through April, peaking at $3.93 a gallon, according to a survey by A.A.A. Alan L. Baum, the principal of Baum & Associates, said that auto sales usually decline when fuel prices go up but that this year they had risen.
Mr. Baum said that from the figures that are available now, it was not possible to determine just how the mileage improvement was achieved, but that it appeared that most of the 1.1-mile-per-gallon gain resulted from better technology, and some from buyers purchasing of smaller vehicles. If small cars traveled two miles more per gallon, other cars 1.5 miles more and light trucks gained 0.5 miles more, that would account for the rise, he said.