Sales of medium- and heavy-duty trucks in Canada fell 12.1% in May to 3,895 units, as all weight classes ended the month in the red, WardsAuto data shows.

Class 8 was down 3.4% on unit volume of 2,696 vs. 2,688 prior-year as Volvo Trucks Mack and Volvo brands combined gain of 33.3% was not enough to offset losses by all others in the sector. Segment leader Freightliner slid 20.8% and lost nearly four points of market share, while the second-highest volume seller International was down 23.4%. For the year, Class 8 was down 3.2% on sales of 11,057 units.

Overall medium-duty sales were down a whopping 26.9% on sales of 1,199 units against 1,580 year-ago, dragged down by double-digit losses in Classes 5 through 7. For the year, the medium-duty group is off a more modest 2.0% on sales of 5,366 units.

In Class 7, segment leader International plummeted 59.9% on sales of only 95 units from 228 year-ago, dropping its share to 32.2% from nearly 50% last year. Kenworth posted a 42.5% sales decline producing an overall loss of 28.7% for parent PACCAR. Ford slid 51.9 % on small volume.

The pattern of losses continued in Class 6 as several brands suffered double-digit declines. Gains on small volume by Ford and Peterbilt were not enough to offset losses by larger-volume players International (-52.3%) and Freightliner (-55.1%).

Class 5 deliveries fell 17.9% on unit sales of 641 vs. 752 year-ago. Mitsubishi Fuso was the only truck maker to post a gain, with sales up 44.4%.

Hino was the leading gainer in Class 4, with deliveries up 321.3%. However, that was not enough to put overall sales in positive territory, as the segment slipped 9.5%.