Can someone explain how the "range" setting on the on board computer works as it seems to have a mind of its own. Yesterday I pull off the motorway and fill the tank to the brim and I go back onto the motorway with the range setting reading 559 miles, having driven a further 35 miles the range reading is now at 629 miles where it stayed for some 25 miles until I arrived home. I realise it is based upon the perceived driving style but does it take its fuel level input from the fuel gauge (which had dropped noticeably by the time 629 miles range was recorded) or is there a load cell and flow gauge?

I would say after you filled up it based your 559 miles range on your previous driving since a last reset. Your further 35 miles was driven more economically and it's telling you that if you carried on driving in that manner, you would extract 629 miles on what fuel was left.

Many a time while driving with a light foot, I have seen the range increase.

Last edited by EYorkshire on 10th Jan 2012 9:23 am. Edited 1 time in total

It takes the average fuel consumption over the last minutes (last 30 miles) and reports it to the fuel level in the tank.
When you pulled away from the motorway, because of the low speed and various maneouvers, the MPG dropped and therefore the range was lower.
Going back to motorway, the average MPG increases and therefore the range increases.