To be honest I've done it a few times in the daily. It said 0 miles remaining when I was on a motorway once and did another 20. Got into a town and it went it to some funky eco mode.. no turbo and a 2k rev limit.. thought that was pretty clever and got me to a station... worst was in a pug hire car, it lied! said I had 20 miles left on the motorway, so eased off loads, services in 10, 2 miles later the screen said 0 miles, 1 miles after that it died!.