LAS VEGAS — Two top Daimler Trucks executives said they expect good long-term growth in sales, both in North America and the world, but said they are not sure when the acceleration will take place from the current sluggish levels of expansion.

HANOVER, Germany — The brisk pace of North American truck sales is helping drive the results of the world’s largest commercial vehicles maker, according to its chief executive.

DUSSELDORF, Germany — Officials of Daimler Trucks AG said their line of Sprinter vans is back on the path to success in North America.

YOUNTVILLE, Calif. — The head of sales and marketing for Daimler Trucks North America said 2012 is likely to end up as a “disappointing year” in general but that sales would exceed 2011’s total.

Daimler AG and its joint-venture partner, China’s Beiqi Foton Motor Co., said they will build a $166 million plant with the capacity to make as many as 45,000 engines a year for its trucks to serve the fast-growing Chinese market.

TOOELE, Utah — As soon as Daimler Trucks offers its North American customers a new part or system, the corporation’s remanufacturing unit, Detroit Reman, is already figuring out how to get used versions of them as soon as possible, so the division can remanufacture them and sell them on the aftermarket.

Daimler AG’s truck division, the world’s biggest truck maker, said spending on a global presence will help it fend off competition from a manufacturing alliance Volkswagen AG is forming with Scania AB and MAN SE.

DETROIT — Detroit Diesel Corp. announced a series of enhancements to its 2013 Detroit heavy-duty truck engines that are designed to improve their fuel efficiency and reduce the cost of running and maintaining them.