Bit Of A Concern

I had a 1.3 Vauxhall Minerva so before purchasing my caravan I upgraded to a 1.7 Diesel Vauxhall Astra and thought everything would be fine. However after studying the handbook I discover that 2 versions of the engine were fitted by Vauxhall one with a lower torque than the other and guess what I have the lower one. Now the towcar matching site says everything will be OK but the Cub site gives the warning that it is a bit underpowered and it may be sluggish and uncomfortable on hills and at junctions. Who should I believe because the towcar site gives much more information about expected performance and does not cause me any concerns? Please don't say upgrade the car because having done that and purchased the van I am not in a position to do so. I checked all the details our about the Astra before purchasing except I didn't relise about the same engine variations.