its also untrue, thats mixed driving, how I would explain it to people is if you do just potter around town, you could see more over time out of charge (so a claimed 280 range could give you 300+) but then the reverse once you go over 50mph say for example we take a 280 mile range car and do 70mph on a motorway like the m25 and then down the m2 your looking at about 155 to 175 depending on wind conditions etc.