Currently travelling on the m25 en route to deepest darkest Kent, the trip computer is showing 68.9 mpg over 255 miles and the fuel gauge is showing 3/4 of a tank left. Reckon it'll make it to 600 on the return journey or do you think it'll run out? have worked out that it needs to do 65 mpg to make it to 600 miles, not too confident that it'll make it