Why the Rotary Engine Is Perfect for Hydrogen Fuel
I doubt any internal combustion engine driving engine wheels has a future. Three phase alternating current electric motors are superior to both piston and rotary motors. Electric motors are more efficient, they have nearly full torque at their full range of speeds and no gear box or transmission is required. If anything in the future, gas motors will serve as backup generators to make electricity when on board batteries get low, similar to diesel electric locomotives that are widely used.