Sluggish Class 6 sales and a modest uptick in Class 8 limited Canada’s April big-truck market to a 13.7% gain, compared with like-2010, according to Ward’s data.

Against a backdrop of double-digit hikes in Classes 4, 5 and 7, volume-leading Class 8 managed only a 2.8% increase on 1,895 deliveries, while Class 6 slipped 2.8% on 185 sales.

Related document: Canada Truck Sales by Weight Class – April 2011

While April’s results kept alive this year’s streak of year-over-year gains, they trailed prior-month’s 22.2% rise and paled in comparison with the U.S. market’s 31.2% jump, its best performance of 2011.

PACCAR’s Mack marque and Daimler’s Freightliner brand likely saved Class 8 from a decline in Canada. Mack sales soared 69.6% on 164 deliveries for the month, while segment volume-leader Freightliner recorded a 65% surge on 513 deliveries.

International’s 25.4% plunge sucked the life out of Class 6. The brand booked 118 sales last month compared with 152 in like-2010.

Hino and Freightliner fared better, but with lesser volumes. Each more than tripled year-ago totals with sales of 48 and 13 units, respectively.

Class 4 was the big winner with a 79.5% gain. Class 5 was second with a 58.1% increase.

Ford was the volume leader in both segments. The Blue Oval more than doubled its like-2010 total with 174 Class 4 deliveries, while its 243 Class 5 sales were more than triple prior-year’s tally.

Conversely, Hino was the biggest loser in Classes 4 and 5 where its sales plummeted 78.6% and 119%, respectively.

Total medium-duty sales totaled 1,145 units for the month, a 37.8% jump.

Through April, medium- and heavy-duty deliveries were tracking 20.8% ahead of like-2010 on sales of 10,192 units.