Servicing and maintaining trucks are essential to safe, profitable freight operations. As the industry adage states, “If the wheels ain’t turnin’, fleet’s ain’t earnin’.”

Uptime is paramount, and in today’s rapidly evolving landscape—termed the Messy Middle by the North American Council for Freight Efficiency (NACFE)—fleets face an unprecedented array of powertrain choices that demand new levels of technical sophistication.

Since 2020, heavy-duty trucks have expanded beyond increasingly efficient diesel engines with advanced emissions systems to include renewable diesel and natural gas blends, battery-electric vehicles (BEVs) with high-power charging, hydrogen fuel cell trucks requiring high-pressure infrastructure, and autonomous systems. This diversity creates both opportunities and significant maintenance challenges.

The Messy Middle refers to a transitional period of abundant viable technologies in a competitive market. New vehicles introduce several hidden requirements that extend far beyond the trucks themselves. Think of them as icebergs, where only a small portion of the giant obstacle is visible.

To navigate these challenges, fleets must address updated maintenance procedures, safety protocols, shop infrastructure, specialized tools and software, technician training, fueling/charging systems, auditing, certifications, and record-keeping. These changes occur alongside continued support for legacy diesels, whose service lives can exceed 20 years. Older platforms are often not backward-compatible with newer technologies, complicating “vehicle geriatrics” and mixed-fleet operations.

In this Messy Middle, technician expertise is central to success. Demand for skilled workers has never been higher, yet shortages persist. According to research from the American Transportation Research Institute (ATRI), two-thirds of shops were understaffed last year. And as more alt-fuel and zero-emission trucks hit the roads, traditional mechanical skills (brakes, suspensions, engines) must now coexist with expertise in high-voltage systems, sensors, computers, software diagnostics, and alternative fuel safety.

Shops also require new protocols such as lockout/tagout procedures, secure high-voltage areas, and fire suppression for potentially explosive gases. Training programs at technical schools must expand, with ongoing certification and recertification becoming mandatory as innovation accelerates. Fleets operating in-house shops must focus on recruiting, training, and retaining talent, while those using third-party providers should demand cutting-edge capabilities to minimize downtime.

OEMs play a critical role by supplying computer-based service tools, over-the-air (OTA) software updates, failure databases, and factory training. However, parts availability remains challenging: proprietary components like high-capacity batteries, carbon-fiber tanks, and specialized sensors face early-production constraints and high costs. A core exchange system for repairs at specialized facilities is likely needed. Software has become integral, shifting technician toolboxes toward digital diagnostics, though physical repairs and driver feedback remain essential.

Artificial intelligence (AI) offers promising solutions for predictive maintenance, troubleshooting, and operational efficiency by mining data from telematics, warranty systems, and supply chains. Infrastructure maintenance is equally vital; charging stations, hydrogen and natural gas fueling systems, and on-site backups (generators, micro-grids) must achieve high uptime or risk immobilizing entire fleets. Industry standards for safety, infrastructure, and shop design are evolving but often lag technology deployment.

In the NACFE report Messy Middle Powertrain Service and Maintenance, we highlight that maintenance costs—including facilities, training, and auditing—significantly influence new truck investments. High uptime depends on skilled technicians equipped with intelligent OEM tools. Alternative fuel systems demand heightened safety focus. Specialization is inevitable, potentially requiring additional staffing. Predictive AI and robust warranties will grow in importance.

Overall, the Messy Middle presents challenges in complexity, parts supply, and workforce development but also opportunities for fleets, OEMs, and service providers that embrace training, digital tools, and data-driven strategies. Success hinges on proactive adaptation to keep trucks moving efficiently through this transformative era.