Boosted by a whopping 50.6% jump in Class 8 deliveries, Canada’s big-truck market recorded a 28.9% sales hike in May, compared with like-2009.

Class 5 trucks were the only segment to see a decline as May builds on a strong April, the Canadian market’s first year-over-year sales increase of 2010.

Related document: Canada Truck Sales by Weight Class – May 2010

PACCAR Inc.’s Kenworth and Peterbilt brands were the big winners in Class 8. Kenworth more than doubled its May 2009 sales, while Peterbilt nearly tripled its prior-year total.

Class 4 enjoyed the next-best performance in May with a 29.8% increase over like-2009. Volume-leader Ford Motor Co. crushed the competition with 144 deliveries, more than twice prior-year’s 72. No other brand recorded more than nine sales.

Class 6 sales rose 24.4% on the strength of International Truck and Engine Corp.’s 100 deliveries, good for a 100% boost, compared with like-2009’s 52 sales. As with Ford in Class 4, no other brand recorded more than nine sales.

International again led the charge, on volume, in Class 7. Its 99 deliveries translated to a 90.7% hike and pushed the segment to a 21.3% gain over prior-year.

But the 34-unit tally of Daimler AG’s Freightliner brand more than doubled its like-2009 total of 14.

Chrysler Group LLC dragged down Class 5 with a 57.8% decline that also held the total medium-duty segment to a 1.4% increase in May.

Through the year’s first five months, medium-duty sales were down 15.9% compared with like-2009.

Total medium- and heavy-duty sales were up 7.2% over year-ago.

emayne@wardsauto.com