MIAMI. Heavy and medium truck sales in the U.S. and Canada should rebound strongly in 2012, according to Daimler Trucks North America (DTNA), largely as fleets of all sizes continue ramping up efforts to replace aging equipment.

“The average truck age is still very high among U.S. fleets, between 6.7 and 6.9 years,” Mark Lampert, DTNA’s senior vp-sales and marketing, explained to Fleet Owner in an interview during a media event here at Miami’s Fontainebleau hotel as part of the company’s rebranding effort for its Detroit component subsidiary, formerly known as Detroit Diesel Corp.

Lampert noted that the maintenance costs for old, high mileage equipment “is eating fleets alive” and its why, despite sluggish economic growth and relatively high unemployment numbers, trucks sales especially for Class 8 units are expected to keep increasing this year.

(Video: Hear Mark Lampert talk about 2012 sales projections.)

However, 95% of the expected sales this year “will be for replacement units only,” he stressed, with few of those units earmarked to help carriers expand capacity.

After five years of what Lampert called “just terrible truck sales,” Class 8 sales are expected to top 232,500 units in 2012 – up from an estimated 160,000 units in 2011, some 125,000 in 2010, and 108,000 in 2009. Medium-duty volumes are expected to grow more slowly, reaching 108,000 units this year, up from 92,000 in 2011, about 72,000 in 2010 and 65,600 in 2009.

Lampert pointed out that more trucks would have been sold in 2011, if not for “a constrained component supply situation, which put an absolute lid on production capacity” in 2011.

“We still see raw material constraints due to global truck demand this year, but not as acute as the shortages in 2010 and 2011,” he added, with demand for trucks in Europe and Brazil falling off, while China moves to more managed economic growth.

DTNA’s projections correspond with the latest report from forecasting firm ACT Research Co. (ACT), which said that with the pace of U.S. economic activity running at around 2% as 2012 unfolds, the heavy-duty truck market should benefit.

“A wide range of U.S. economic data reported in the last few weeks have been stronger than consensus expectations,” explained Sam Kahan, ACT’s chief economist in the firm’s January issue of its North American Commercial Vehicle Outlook.

“However,” he continued, “they are incidental to underlying trends, as the fundamental factors affecting economic growth remain largely unchanged. We do believe that the heavy-duty truck market will continue to benefit from healthy trucker profits and rising used-truck values.”