Watching the fuel consumption under various circumstances revealed some interesting data. The journey up was made in cold rainy weather neccesitating the use of lights and wipers, the return journey was made in sunshine with temperatures of 25C+, so it seems that warm dry weather can give an extra 5 mpg when driven economically.
I also noticed that when the engine was cold, first start of the day the fuel consumption was down to the low 50s for the first 5-15 miles depending on ambient temperature and then sat at about 60 mpg on cold days but rose to 65+ on hot ones.
Peter
Peter