The break-in period for the Diesels is 1,600kms, ours is an ex Subaru executives car and has 10,000kms on the clock so it's already through the break-in time

I have read though that it takes around 15,000kms for the fuel economy side of things to level itself out...
We took her for a trip through the 14 River Crossings track yesterday out at Killarney and she did really well (I still think a small lift would be of great benefit

) She even got a little mud on her
The Husband agrees that a bash plate would be beneficial
We also opened her up a little on a straight bit of road - not the smoothest of surfaces being a back road out in the sticks but it still had good visibility and got her up to 170km/h and had only just changed to 6th gear so she still a fair bit to go!