So for the last three fill ups, I've compared the vehicles readout to my own calculations. And am pleased to report that the car is under reading by about 1 mpg. Not a lot I know, but at least it gives me the confidence to rely on the OBC knowing that the reading is on the low side.

Don
 
							




 Never anthropomorphise computers. They hate that.
 Never anthropomorphise computers. They hate that.
