All major U.S. Class 8 truck manufacturers saw sales drop in September from the year-ago period, with total Class 8 sales slipping 29 percent to 7,769 units
, according to Automotive News. U.S. sales of medium- and heavy-duty trucks were down 22 percent in September to 20,009 units.

Truck sales have been trending downward every month since January 2007, with truck sales falling 33 percent for the first nine months of this year.

Class 6 sales fared the worst during the month, dropping 30 percent to 2,000 units, followed by Class 8 sales. Sales of Class 4 and 5 trucks slipped 17 percent and 25 percent, respectively. Class 7 came out on top, with sales down 3 percent to 3,428. All categories saw lower sales on a year-to-date basis as well. Through September, sales of Class 1-3 trucks declined 30 percent to 3,492,161 units. For Class 4-8, sales were off 33 percent to 165,112 year-to-date.

Ford Motor Co. saw the least decline in sales among all truck makers in September, falling 8 percent to 5,228 units. This was followed by International and Freightliner, with sales down 21 percent and 27 percent, respectively.

All major Class 8 manufacturers reported diminished sales for September, including Freightliner, down 29 percent; International, down 24 percent; Kenworth, down 9 percent; Mack, down 36 percent; Peterbilt, down 21 percent; Sterling, down 76 percent; Volvo, down 36 percent; and Western Star, down 48 percent.