For the last two months i've been getting maximum of 24.4mpg. I do a lot of town driving and on the way to work i rarely exceed 40mph. Round September time i was getting about 29/30 and at one point (i think the car had a funny moment) it went up to 39mpg really quickly with no change to how i was driving. It's had the Diverter valve replaced in the last 6 months so i can't imagine it is that again, could it be running rich? what would cause that? or are there any other theories you guys might have? I'm driving to Cornwall from Oxfordshire in a few weeks and 24mpg for a 200 mile drive will be a killer.