Good 30-mile Wh/mile Average

[Scrith]

On the way back from Yosemite recently...

 

[ahirbe]

Wow! an I thought that getting 10 miles for 5 the other day was a steal.

 

[Unpilot]

I wonder what would need to be engineered to make the X or S or Model 3 flat towable.
If you started at the top of a infinitely tall hill and just coasted down it would obviously charge the battery as the OP shows.

So to me it seems doable....and I know many (myself included) would like this option.

/hijack over