Class 8 truck OEMs saw May sales down 8.5 percent from April
, according to data by WardsAuto.com. May levels were still 13.5 percent higher than the year-ago month, when Class 8 sales totaled 6,955 units.

May Class 8 sales came out to 7,895 units, down from April's 8,627 units. For the first five months of this year, heavy-duty truck sales are at 40,361 units, compared to 35,451 over the same five-month period of 2009.

International saw the highest sales of Class 8 vehicles in May, at 2,684 units, followed by Freightliner, with 2,233 trucks sold. Kenworth saw 953 units sold, while Peterbilt sold 776 units, and Mack sold 626. Sterling and Western Star each sold 81 trucks in May, the lowest figures of the month.

Unlike the Class 8 market, Classes 6 and 7 saw some improvement over April. Class 6 posted sales of 3,071 units in May, compared with 2,227 units in April. Class 7 manufacturers sold 2,647 units, up from 2,568 in April. During the year-ago month, Class 6 reported sales of 1,304 units, with Class 7 at 2,887 units.