Demand for truck and trailer parts grew roughly 2% in 2014 to $26.19 billion dollars, and it will continue to grow, albeit at a slower pace this year and through 2019, according to John Blodgett, VP of sales and marketing for MacKay & Co. Speaking at the 2015 Heavy Duty Aftermarket Dialogue, Blodgett said 2014 medium- and heavy-duty truck and trailer parts sales were driven by record new truck sales in 2005 and 2006. Trucks seven to nine years old have the highest parts consumption, he explained. The steep drop off in new trucks sales in 2007 and the following years will depress parts sales over the next five years, "but we'll still see steady, if not huge growth," Blodgett said. Turning to other changes in the U.S. heavy-duty truck market, Blodgett pointed out that the Class 8 population hit a record high average age of 9.72 years in 2011 and has essentially stayed at that advanced age through 2014. However, Blodgett also pointed out that major truck components are living longer than ever. For more of Blodgett’s analysis, along with additional coverage from HDMA, see the full story on FleetOwner.com.