Infrastructure-Oriented Assessment of Energy Efficiency and Estimated CO2 Emissions at the Combustion Stage of a Diesel–LNG Dual-Fuel Mining Dump Truck Based on Field Telemetry Data

Haul-road condition can affect traction demand and diesel-to-LNG substitution in mining trucks. We evaluated a 140-t truck at the Ekibastuz coal mine using 180 registered cycles (88 diesel-only [DOM], 92 dual-fuel [DGB]), 24 road segments, 36 defect events and 30 matched fuel-mode pairs. Mean ECM-reported substitution was 30.61% across DGB cycles. In matched pairs, diesel use declined from 34.00 to 23.76 L/cycle, a mean saving of 10.24 L/cycle (95% CI 9.53–10.95); calculated combustion-stage CO2 declined by 7.10%. Total fuel energy, specific fuel-energy consumption and cycle time did not differ significantly (p > 0.30). Across Good-to-Poor road classes, engine load increased from 66.11% to 74.40% and substitution from 28.97% to 32.31%, while specific fuel-energy consumption increased from 5.91 to 6.72 MJ/(t·km). The load association persisted after temperature and wind adjustment and shift-clustered inference. Reference-state haul-road energy penalty was associated with rolling resistance and roughness, but remains dependent on a supplied reference input. The results distinguish diesel displacement from improved transport energy performance and are conditional on the cycle register. They do not establish causal road effects or a life-cycle climate benefit.