When I first bought my S1 about 7 or 8 years ago I checked the fuel consumption on the long run home from the Morgan garage. I was amazed to be seeing around 30 mpg (using brimmed tank to brimmed tank method), admittedly with very little traffic & driving at moderate speeds as I was still aquainting myself with the car.
I've never had reason to check the fuel consumption again but I have always enjoyed driving the car with a sensible but entertaining right foot, as I just love the sound of my twin side exhausts I had fitted! Never had the fuel gauge give me cause for concern but as a matter of habit I never let it drop below 1/4 full. I am the same with my modern everyday car as well.
Just one question about your photo as the side of the road, are the crowd admiring the car or the lady with the bike?