Quote Originally Posted by GerH
Quote Originally Posted by ciars
Hows the battery and coolant system looking (thermostat)? What does the car indicate (from the hidden OBC menu) after idle and warm versus crawling in traffic (again warmed up) versus driving at 80-100km/h when warmed up?
If I reset the MPG on the motorway it will show up to 45/50MPG then as I'm off the motorway it's going down and in stop start traffic it's very poor
Forget the OBC MPG - access the hidden menu in the OBC and post up the temps for the various scenarios I posted up. Here's the DIY on accessing that menu: http://www.bmwhaus.ie/forum/showthread.php?tid=46

At least then we can rule in or out, the cooling system.