Battery electric trucks are not a cost-competitive option against diesel for long-haul trucks in the U.S. in the scenarios presented above. However, we extend our analysis to various parameter values to identify the feasibility space where long-haul trucks can reach cost parity with diesel in the long term. In section 4.1, we consider the effect of unit electricity and battery cost as they have high uncertainties for future scenarios. We anticipate regional differences in electricity costs as the share of renewables increases, given their greater sensitivity to location compared to fossil fuels. For battery costs, future projections rely upon technological breakthroughs that are currently aspirational. Next, in section 4.2, we evaluate a scenario with a reduced aerodynamic drag coefficient which significantly impacts the computed TCO and has been heavily researched by the DOE SuperTruck program. Finally, in section 4.3, we discuss different operating strategies such as intermediate charging and battery swapping which could be potentially implemented to allow BETs with smaller batteries to cover long-haul routes.