this would be awesome. However, I think these guys either missing some power loss contributions or talking about purely mechanical power or using really streamlined / lightweight car example or all of the above. I've used Formulas
from the book 'Build your own electric car' before and am coming out at 27hp required for a 3500lb BMW to move at 60mph (as opposed to 15hp that these guys quote). My calculation gives me ~330 Wh/mile which is in the right ballpark for 60 mph.
This gets me the range of just shy of 100 miles at 60 mph. At 40 mph, it's 140 miles or 40% higher.