Heavy growth in recent years in the midrange (Class 3-5) medium-duty population is the strongest driver for increased aftermarket parts sales entering 2026, Commercial Motor Vehicle Consulting (CMVC) Principal Chris Brady reported Wednesday during a MEMA Pulse webinar.
Speaking Wednesday about the wild changes to freight levels, equipment demand and capacity trucking has experienced in 2025, Brady says there are positives and negatives to be found for aftermarket part sales opportunities in all truck classes these days. The Class 8 tractor space receives the most attention due to its outsized market influence but it’s not the only market that needs parts.
Brady says the truck fleet is evolving. Smaller classes have boomed since the pandemic and with trade uncertainty continuing to depress Class 8 growth potential, now is a great time for aftermarket parts operations to enhance their medium-duty parts operations and keep sales up until the Class 8 recovery begins in earnest.
When will the Class 8 recovery begin?
To some degree, Brady says this is already happening. The line haul market represents a large share of Class 8 market and CMVC research indicates these operators have been right sizing their fleets throughout 2025. After being under capacity exiting the pandemic, carriers extended trade cycles, ordered freely and grew their fleets liberally into 2023. Then when freight peaked, and then began to recede, they were left with more trucks than loads.
Brady says capacity in the line haul market returned to historical percentages in 2025, albeit with fewer trucks in operation. This is good and bad news. An older fleet (CMVC estimates the average age of a first owner’s truck will grow from 7.04 years in 2024 to 7.28 in 2027) with a strong utilization rate consumes a lot of parts, he says, but the larger than average share of sidelined trucks — either shifted into the used truck market or being harvested for components — limits the market’s upside.
Changes in U.S. Class 8 fleet capacity from 2024 to 2027.CMVC
Understanding the medium-duty market
In the smaller classes, Brady says similar market cycles are underway but on different schedules. He says the Class 6-7 is about a year behind its Class 8 counterparts, utilization rates falling now and expected to normalize and then increase moderately in 2026 and 2027.
As for Classes 3-5, Brady says the dramatic expansion of that fleet in the prior decade means a huge numbers of vehicles have recently entered their peak years of aftermarket demand. He says the rate at which that market grows will slow in the years ahead but today remains very strong, and has fewer utilization and used truck issues as the larger classes.
Overall market analysis
Brady says CMVC’s Parts Leading Indicator (PLI) has been creeping upward after bottoming out in December, mostly driven by midrange market expansion and improved Class capacity.
He says trade certainty would be the biggest driver of faster growth. Global economic stability could increase business investment, spur employment growth and impact consumer spending, all of which would spur the transfer of goods. But until that happens, he expects fleets will continue adjusting investment and spending in response to soft to sluggish freight environment, buying only the trucks and parts necessary to maintain business profitability.
