Washington ? The average fuel economy of 2006 model year vehicles remained constant compared with the previous year, the government reported Monday.

The Environmental Protection Agency said in its annual report that the estimated average fuel economy for 2006 vehicles was 21 miles per gallon, the same as 2005 models.

Honda Motor Co. had the highest fuel economy rating by manufacturer, 24.2 mpg, followed by Toyota Motor Corp., with a 23.8 mpg average. But both Japanese automakers saw their averages drop from the previous year as they placed more of an emphasis on larger vehicles.

DaimlerChrysler AG had the lowest fuel economy rating – 19.1 mpg – followed by Ford Motor Co., which improved 0.5 mpg to reach 19.7 mpg. General Motors Corp. also showed improvements, posting a 20.5 mpg average.

The EPA report showed fuel economy averages 5 percent below the peak of 22.1 mpg in 1987-88.