On: Electric recumbent bikes are 80 more efficient tha...

[ok123456]

Need to normalize by vehicle weight and engine output to compare efficiencies.

Yes, in absolute terms a smaller, lighter vehicle that only needs to produce a maybe 1kW to move will be more efficient.

[tcfhgj → ok123456]

You should rather normalize regarding payload weight

[ok123456 → tcfhgj]

I don't want to have to swap out my engine if I decide to carry an extra passenger.

[tcfhgj → ok123456]

You don't need to do that. it's just for comparison