Spa trip 41 mpg! :-)

[ainarssems]

60mph average 29.6 mpg
70mph average 27.3 mpg
80mph. average. 26.5 mpg
I've only tried it once, but not on the same route! so I need to try it a lot more.
Anybody else tried this?

Less speed=less air resistance and less friction=better fuel economy. Simples

Air resistance is insignificant at speeds below 20mph and you would want to keep car in as high as possible gear for better economy. You need about 40 mph to drive in fifth on D2 so you would most likely get best economy somewhere in 20-40mph range.