Insignia 240psi or 263psi

GARYG53

I have decided to buy a 2013 vauhall Insignia hatchback to tow my 1400 kg van. I cannot decide betwee the 2 diesel engines as the 240psi has better tax mpg and surance figures than the 263 engine. BUT woud i be better with the stronger engine to pull this
weight. I wonder if there is anyone with experience of towing with either of these engines that would help my decision. Please!!