U.S. big-truck sales jumped 30% in February, compared with like-2010, more than doubling the segment’s impressive prior-month performance and extending a winning streak dating back to January 2010.

All medium- and heavy-duty groups, with the exception of Class 4, posted gains compared with year-ago. The last time big-truck sales slid year-over-year was December 2009.

See Related Content: U.S. Truck Sales and Inventory by Weight Class - February 2011

However, February marked a second consecutive monthly downturn for Class 4. Its deliveries plunged 38.2% to 585, from year-ago’s 947. In January, the group saw sales plummet 59.7%.

International and Isuzu were the only Class 4 gainers. Their sales rose 72.4% and 102.5%, respectively, but Isuzu sold 241 trucks in the month, International’s tally was a relatively soft 50 units.

Class 5 sales more than doubled from like-2010 to 3,043 deliveries.

Of the high-volume players, Chrysler posted the strongest month in the group, with sales rising 178.2% to 690 units. Ford deliveries grew 160% to a class-leading 1,970 units.

Class 6 demand improved 22.4% to 2,750 units, from 2,247 year-ago. Daimler paced the field, more than doubling to 1,172. The truck maker’s Freightliner brand provided the bump, as its sales nearly tripled to 1,160.

Class 7 deliveries rose 18.8% to 3,293 units, from 2,771 in like-2010. Daimler again saw the greatest success, as sales swelled 50.1% to 1,409. Freightliner was the catalyst, as the brand’s deliveries jumped 52.4% to 1,405.

Total medium-duty sales in February increased 29.3% to 9,671 from 7,478 year-ago.

In the heavy-duty segment, sales rose 30.8% to 9.712 from 7,427 in like-2010. Volvo truck led the field on sales of 2,112 units, compared with 1,283 year-ago, for an increase of 64.6%.

Medium-duty stocks at the close of February stood at 26,479 units for a 66 days’ supply, compared with 29,949 and a 96 days’ supply in the year-ago period.

jamend@wardsauto.com