Ford sold 195,827 light trucks and 174,981 cars in May.
Ford sold 3,608,911 vehicles, up 12 percent for the year.
Ford sold 116,642 cars, down 11.4 percent from the corresponding period a year ago.
Ford sold 97,006 domestic vehicles, up 11.9 percent from a year earlier.
Ford sold 23,059 light trucks during the period, a decline of 29.8 percent.
Ford sold 32,364 cars in the 10-day period, a decline of 20.5 percent.
Ford sold 75,939 cars; its total of 46,033 light truck sales was a record for the period.
Ford hoped to sell 5,000 City cars a year, but has sold a total of just over 1,000 in three years.
Ford sells more than six million vehicles a year worldwide.
Ford sold more than 8,200 of the giant trucks, a company executive said.