My commute is 40 miles, lanes, A roads and M6 (currently at 50 mph all the way). With a few overtakes on the B and A road, I am getting 47.5 mpg, with it in normal engine and ACC mode.
For a very powerful car, it is exceptional MPG, primarily due to the 60 50 on the M6.
A month ago I drove from the midlands via Glasgow, and Skye to Harris - 600 miles and again it got 45 mpg with ACC set to about 75 on the Mway the whole way.
Impressive engineering - power and economy both.