Jan 5 (Reuters) - The average fuel economy of new vehicles sold in the United States in December fell marginally as consumers bought more fuel-thirsty trucks than more efficient passenger cars, a report showed.
The average fuel economy slipped to 25.0 miles per gallon (mpg), down 0.2 mpg from the revised value for November, according to a report by University of Michigan Transportation Research Institute.
The report comes at a time when automakers have been demanding a cut in the fuel efficiency standards for 2025, arguing that the target was difficult to achieve as consumers prefer larger, less efficient vehicles.
The Obama administration finalized rules in 2012 to double the fleetwide average fuel economy to 54.5 mpg by 2025, but the Environmental Protection Agency lowered it to 51.4 mpg based on rising number of trucks.
The drop in December number likely reflected the increased numbers of light trucks in the sales mix versus passenger cars, said Michael Sivak, who heads the Sustainable Worldwide Transportation research group at the university.
America's love affair with gas-guzzlers like Ford Motor Co's bestselling F-Series pickups is showing no signs of fading.
The total number of light trucks sold in the United States rose 4.3 percent to about 10.90 million in 2017, while sales of passenger cars slumped about 11 percent to 6.3 million.
The average fuel economy of new vehicles sold in 2017 was 25.2 mpg, unchanged from 2016, according to the report. (Reporting by Ankit Ajmera in Bengaluru; Editing by Arun Koyyur)