Many years ago, I owned a Honda Goldwing (GL1000) outfit.
Although I never tried hypermiling it, it returned 41mpg (imperial) riding easy or hard as a solo and only dropped to 38mpg or so with the sidecar attached.
I've never ridden in snow, but if it's anything like climbing a slope on wet grass, lack of traction can be a problem.
I love sidecars as weekend toys, but they aren't practical transport when compared to a small tin top when the weather turns foul.
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