Strong sales of pickups and sport utility vehicles are keeping national fuel economy at a 20-year low, the US government says, according to a report from Associated Press (AP). The focus on bigger, more powerful vehicles led to the Environmental Protection Agency finding that average gasoline mileage for 2000 model year passenger vehicles was 24 miles per gallon, the same as 1999 and the lowest since 1980. The figure had climbed to 25.9 mpg in 1987 and 1988, AP said.