So. fuel consumption over Xmas??

[cheapo]

51mpg for me on the stupid 'modern & economical' 1.6 HDi...

That's surprising.

While I realize that my 'estimated' mpg is just that, I know I was easily covering 50 miles for each 'gallon' during the working week. So the long trip had 50+ as a foregone conclusion.
.
 One re-map claims a 5mpg increase, plus more power obviously. But my engine is already half way through it's expected life and although it would be more fun, I'd have to have enough money in the bank to immediately buy a replacement, if I was going to tune it.