Amazing… I would love to see what m/kWh they got doing that! I can’t imagine it would be good!
A bit of my own experimenting, I found that driving at 70mph on motorways netted me around 3m/kWh, Vs 4 at 60mph, so a big difference for a minimal time saving gain! Although overtaking lorries can be a bit of a long affair! Sorry if you get caught behind me!