With the roof bars off, the fuel economy has gone back up to 50.9mpg. In fact, earlier today, on a run to Cupar, the computer displayed average mpg of 51.0. I am starting to get the fuel economy back to the 54 to 55 range where it was about a year ago (minus roof bars).
One thing I think is going against my favour is that most of my journeys last between 5 to 10 minutes long. This is to run the children to school - a distance of two miles. Typically the engine starts from cold, runs to the point where it is warmed up, then, journey over. I think if I were doing regular, longer runs then I'd see an improvement in fuel economy. For instance, on a twenty minute run to St. Andrews during the week the mpg for that jorney was in the low 70s. This was a good straight, long unbroken run on a fairly level road combined with running the engine/hybrid system at optimum temperature - and the results speak for themselves. There are so many factors affecting this mpg figure, aren't there!