The 2026 State of Sustainable Fleets report shows US commercial carriers moving away from single-technology bets on alternative fuel. The expiration of commercial zero-emission vehicle tax credits worth up to $40,000 per unit, combined with the rollback of greenhouse gas vehicle standards and the cancellation of California's Advanced Clean Trucks rules, left fleet managers with considerably less policy certainty heading into the year.
Despite those headwinds, alternative fuel adoption continued to grow. The Cummins X15N 15-liter natural gas engine finished its first full commercial year on a strong note: 71% of fleets running it reported lower costs compared with diesel, and 59% reported savings over other natural gas vehicles. Medium- and heavy-duty battery-electric vehicle registrations rose 21% in 2025. Propane adoption expanded steadily, with more than 23,000 propane school buses operating across 1,100 districts in 49 states. Midwest school districts locked in propane prices between $1.32 and $1.90 per gasoline-gallon equivalent, between 47% and 63% below gasoline's 2025 average.
Hydrogen continues to face steep economics. Fleets paid $18.86 per kilogram after incentives, roughly 89% to 135% above the cost of diesel. Industry analysts put the break-even point at $8 to $10 per kilogram. Regional Clean Hydrogen Hub funding cancellations and the exit of two Class 8 fuel-cell startups left the hydrogen segment in its weakest position yet.
AI adoption among fleet managers reached 48%, with route planning, dispatching, and maintenance diagnostics leading use cases. Autonomous freight operations are also expanding: Volvo and Kodiak are each running driverless Class 8 trucks on commercial freight lanes in Texas.
Source: FreightWaves -- https://www.freightwaves.com/news/state-of-sustainable-fleets-2026