I see that I have previosly responded to this thread with some weird text...
I've noticed that my car increases revs to ~1k in 3 cases:
1) hot weather (with AC on - needs extra power for it). If you turn AC off, the revs should decrease (not immediately, though);
2) cold weather - while engine is cold, it's normal thing. Usually goes to normal after some warming up.
3) DPF regeneration on.
So, in hot weather try to avoid AC in a test drive and watch revs then. In cold weather after certain warm up revs should be in the normal range. DPF thing - well, until it's finished.
At least for my car these high revs are common thing in certain situations.