I have roughly worked it out using the brim method and no way is it doing the 16mpg on the message centre. I estimate it around 26mpg and we did 220miles on nearly a half a tank. So running at 55 mph on the good roads, it seems to increase. Not bothered with the output, it's running and starts well in the cold. So leave it to warm up and slowly increase the speed, cars a pleasure again to drive.