US heavy truck sales took another dive in May  with the  Class 8 heavy duty market plummeting 12.8 per cent to 17,312 units with  Volvo trucks posting the greatest drop, falling 31.3 per cent while its sister brand, Mack, slipped 9.7 per cent and International also took as sharp 21.4 per cent decline.  Western Star was the only brand to grow across the month, up 28.4 per cent on relatively small volume

Year-to-date US Class 8 Heavy Duty sales were down 12.3 per cent compared with the first five months of 2015.

US Medium-duty sales fared better as all classes surpassed year-ago’s daily selling rate. Overall, the group was up 16.2 per cent, with monthly volume at 16,868. For January-May, sales were 16.6 per cent above the same period last year.

Class 7 sales hit 4,501, up 18.9 per cent with  Freightliner rising 21.7 per cent while other big gains also were seen by Kenworth (+32.3 per cent), International (+18.5 per cent) and Peterbilt (+15.4per cent). Ford and Hino posted declines of 10.8 per cent and 4.1 per cent, respectively.

Class 6 sales increased the most, shooting up 37.3 per cent with 5,304 units. Freightliner recorded a 7.7 per cent drop, allowing it to lose top rank to Ford, up 80.9 per cent. International posted the highest gain within the group, jumping 82.0per cent. .

Class 5 was the slowest-growing medium-duty segment, up just 2.5 per cent to 5,771 orders. Chrysler up 14.2 per cent, Isuzu (+54.9 per cent) and Hino (+17.1 per cent) posted double-digit gains, while Ford  dropped 5.2 per cent and International was  down 8.8 per cent were down.

Class 4 sales totaled 1,292 units, up 4.5 per cent. Isuzu’s domestic lineup helped the group stay in positive territory with a 61.9 per cent leap, while its imported models were down 37.3 per cent. Ford posted a 17.1 per cent gain.