Data Confirms Initial Conclusions:
The Messy Middle Final Findings Report

Run on Less – Messy Middle measured real-world performance from 14 Class 8 tractors operated by 13 participating fleets across four energy pathways: diesel/renewable diesel/biodiesel, compressed natural gas/renewable natural gas, battery electric, and hydrogen fuel-cell.
Data Confirms Initial Conclusions: The Messy Middle Final Findings Report collates the major findings of the five reports from the Run and also puts them in context with the myriad of factors influencing freight’s transition from older, less efficient, costly and higher emission powertrains to the latest production technologies offered in diesel, natural gas, hydrogen and electric powertrains.
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Messy Middle Final Findings – Executive Summary August 2026
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Messy Middle Final Findings Report August 2026
The initial findings are:
- Powertrain technologies in the trucking industry are constantly evolving yet must compete directly on cost and performance in an environment of shifting regulations and incentives.
- Fleet owners, their customers, and the public continue to value sustainability efforts while still looking for good returns on their investments.
- Fleets have more powertrain choices from OEMs, which is creating challenges given the increasing segmentation of the truck market.
- Recent significant powertrain advancements include a 15L natural gas engine, 400+ mile battery electric vehicles, high power fast charging stations, increased availability of renewable natural gas and bio and renewable diesel, and new high-volume OEM entrants.
- All the powertrain technologies are improving and revealing new benefits. However, challenges persist, especially with fueling/charging infrastructure, weight, and cost.
- Natural gas trucks are satisfying the needs of diesel with more power, torque, range and quick fill times.
- Battery electric truck range, weight and costs are becoming more competitive with diesel trucks in similar duty cycles.
- While production of renewable fuels is increasing, it remains well below what is needed for wide-scale adoption by fleets.
- Hydrogen in freight movement is still a nascent technology but is showing promise in certain use cases.

After analyzing the data from the Run, NACFE found that its initial findings were valid. Below are some examples of how additional analysis of the data served to validate NACFE’s initial findings.
- Fleets universally need powertrain technologies to make sense economically. The math exposed in the Run’s Forecasting The TCO of Powertrain Alternatives: The Messy Middle Co$t Report highlights the multitude of factors fleets must now consider in making their capital investments, and fundamental to that is the fact that freight is a business requiring operations to have positive cash flow.
- The finding that many fleets still care about emissions and sustainability was reinforced in the From Source to Highway: The Messy Middle Emissions Report. Many fleets care about their vehicle’s impact on the health and quality of life of the communities in which they operate.
- Fleets have an unprecedented level of choice in the Messy Middle. OEMs are offering many alternatives in their product lines, reflected by extensive R&D investment over years and recognizing that the Messy Middle is all about providing fleets with choices. The age of one-size-fits-all truck solutions is giving way too much more purpose-built solutions optimized for specific fleet duty cycles and all will need well-trained, properly equipped technicians.
- The initial evaluation of the potential market penetration for the new Cummins 15L natural gas engine seems spot on. Three OEMs — Freightliner, Kenworth and Peterbilt — have already included it as an official option.
- The Run findings noted Class 8 BEVs such as those from Tesla, Volvo, Windrose and others, were entering the market with greater range than previously seen. Fleets using BEVs are demonstrating initiative in utilizing short opportunity charging to extend miles per shift and multi-shift operations by adding quick additional electricity to the batteries rather than defaulting to only one charge cycle per day.
- Terrain, Technology, and Telematics: The Messy Middle Operations Report confirmed the initial Run assessment that all powertrain technologies are providing improved efficiencies over older fossil diesel vehicles.
- Hydrogen remains a nascent technology. Two Hyundai’s FCEV’s did participate in the Run, but the company is reportedly developing a more North American specification for production in the 2027 to 2028 time frame. Other OEMs, such as PACCAR and Daimler, have delayed production launches of FCEV Class 8 trucks.

NACFE’s analyses also have reinforced the critical need for the Run on Less biennial demonstrations to showcase new production technologies in real-world commercial operations and the willingness of fleets to share their experiences.