I have a 2011 Titanium X 140 auto.

It has a weird what I think is a fault.

At constant speed either with cruise or just with the foot say 40mph there is a slight and continual fluctuation in engine speed. You can see the rev counter sort of fluttering up and down and just about feel it in the car. This is at all held speeds. I have not experienced this with any other auto that I have driven.

It almost feels like the engine is missing or the gear box slipping.

Not only can it be seen in the rec counter you can just about feel it as well.

I did take out ford protect warranty when I bought it 4 weeks ago but was wondering if this is normal or something I should get them to look at.

I had a problem that was similar to this but it was a manual, focus 2.0 tdci on a 2005 plate. Occasionally at a steady speed the rev counter flickered, I took it into my local dealer have it looked at and they couldnt find an issue, after I had upgraded my car to a newer focus and traded mine in, the salesman told me that the new owner had brought the car back because the clutch and flywheel had failed about a month after I had traded it in.