> For one thing, gas/electric hybrids exist and have been successful despite requiring two engines. Hybrids are pretty simple. Toyota Hybrid Synergy Drive is

> For one thing, gas/electric hybrids exist and have been successful despite requiring two engines. Hybrids are pretty simple. Toyota Hybrid Synergy Drive is basically a replacement transmission and is much more basic in design than a conventional automatic. HSD reduces the number of planetary gear trains to just one, replaces the large number of clutch packs with two electric motors, and eliminates the torque converter all together. One could build a working HSD unit using 1920s technology. It just would need to be manually operated (probably using a lever similar to an aircraft throttle).