This lil bugger was used to collect my Brother's new car last weekend- managed 485.3 miles on 40.98 L- a very pleasant 53.86mpg (imp) or 44.81mpg (US)
Most of that was done at an indicated 75 as we were on a short timescale. I reckon If I can get a long run at 60-65mph, she'd be good for 58-60mpg