19000miles on clock now, avg 37.6 mpg on trip computer, using v power, but when we had our heat exchanger changed out last year it was dropped off with a average of 25 or 27 mpg reading, I left it for a good few months and there wasn't any real change. then decided to reset and it started reading 35 avg. so all I'm saying is don't trust it ( computers ), the tank brim method is the way I do it if I really want to know more precisely. After chatting with Caldean I have tried to drive more economically with good results mainly by being in the correct gear for the road condition and speed.