U.S. sales of medium- and heavy-duty trucks in October continued their momentum from last month with a 5.2% gain on like-2009 to 18,522 units.

Year-to-date deliveries grew 10.8% in October, compared with year-ago, to 176,530.

Related document: Ward’s U.S. Truck Sales by Weight Class – October 2010

Class 5 led the pack, with sales soaring 55.0%, while Class 6 and 7 saw slight increases of 0.1% and 5.0%, respectively. Class 4 made a dismal showing in the month, with deliveries tumbling 58.5%.

While most Class 5 manufacturers showed gains, the largest came from International Truck and Engine Corp., up 139.2%. Volume-leader Ford Motor Co. followed with a 133.6% year-over-year increase.

Ford led Class 6, with sales surging 115.3% to 602, compared with like-2009. Volume-leader International, however, posted a 37.5% decline to 710 units.

International dominated Class 7 in volume, with deliveries up 14.2% to 2,000 units. Daimler AG’s Mitsubishi Fuso brand saw the largest percentage gain, up 211.1% from prior year, but on a meager 3 units

Daimler’s total Class 7 sales in October, including the Freightliner, Mitsubishi Fuso and Sterling brands, slipped 2.3% from year-ago to 1,116 units.

Total medium-duty deliveries in the month grew 4.9%, compared with like-2009, to 9,861.

Sales of heavy-duty Class 8 trucks climbed 6.3% in the month, largely on the back of Daimler’s Freightliner brand’s 49.8% spike to 3,128 units.

October inventories of Class 8 and medium-duty trucks declined in both units and days’ supply. Class 8 had a 68 days’ supply (22,032 units), down from 80 days (24,235) year-ago. Medium-duty days’ supply fell to 70 days (25,387) from 84 (29,410) in like-2009.