Another week gone by and I am pleased to say everything is excellent. No problems of any kind.
I have started a new tank doing the journeys I normally do ie. local and drives of 20 miles or so. It is very hilly (on the pennines) and motorway to leeds or sheffield.
Before I had to work hard to get around 61 - 62 mpg. Now it is 70-72 mpg with less effort and faster overall speed. It's subjective but 10-15% faster.
I feel there is room for further improvement of the figures as is but I would love to fit a IMAC&C , as having experienced Peter's the gains would be huge.