Underpowered Autotrail Savannah 2.3 diesel 2010

jimmicks

When I bought my motorhome new, I had it wow powered at the dealership. The vehicle runs ok on flat roads etc, and accelerates well at slow speed, but struggles on hills, despite carrying no water, or other heavy items on board. My last trip from Aberdeenshire
to Edinburgh was the worst yet, as I had frequently to engage 3rd gear on several minor inclines, despite the vehicle being completely empty apart from my wife and I and a change of clothes. The lack of power is getting worse. The vehicle has done almost 10,000
miles. Might this be the wow, or perhaps an engine issue. The vehicle has been serviced and has just passed its MOT and emmissions were fine then. Has anyone else had this problem?