U.S. sales of new cars and trucks were expected to drop in August, ending summer on a low note for the auto industry.

Ford's sales were down 8 percent compared to last August. More automakers will report sales later Thursday.

Overall industry sales were expected to slip 5 percent to 1.5 million vehicles, according to J.D. Power and LMC Automotive. It would be the fourth month this year that sales have been flat or have declined on a year-over-year basis.

This isn't unexpected. After six straight years of growth — and record sales of 17.5 million new vehicles last year — the industry has been bracing for a plateau as consumer demand wanes. Total sales through August are now expected to be flat compared to a year ago.