2.7 TD V6 What RPM's at What Speeds.

Hello All,

I've got a 2005 face-lift model auto and I've recently had an AF kit gear box service. I've noticed now though that the engine seems to be holding high revs at relatively low speeds. I know these engines are not high revvers like the petrol's with max on the dial of 5 and red line at 4000rpm. When cruising at 50 mph i'm hovering around 1800 rpm and i've knocked it into 5th on the manual side and its not changed gear. What sort of RPM at what speeds should i be expecting? Whats typical when on cruise at 50mph? 

Thanks Ady