Re: Will it.....
Case in point, @Richard 12:
Car: VW Passat BlueMotion 2.0L Diesel
Route: Oxford - Galashiels - Duns - Galashiels - Duns - Warwick Services (M42) = 731mi.
I could've chanced the extra 36 miles to Oxford, but I decided not to (given how Diesels don't like running out of fuel). The trip bar the Galashiels - Duns segments was driven primarily on cruise control (and not at Sunday-drive toddle speeds either).
I couldn't believe my eyes when I still had 38-odd miles in the tank by the time I hit the services... :-)