Better, surely, to keep the 156s and ditch as many 150s as possible? They're so much better from a passenger perspective. In comfort terms, I'm as happy with one of the refurbed 156s as I am with a 195.In a word: no. The franchise is losing money and new units are expensive. The only realistic upgrade would be swapping units with better ones owned by the same Rosco. There are enough 158s and 175s becoming available to scrap all Northern 156s, a small number of 150s and the least reliable Northern 158s. Some routes require units that have doors at thirds which makes 150s harder to replace. Getting first refusal on TfWs 769 fleet (if it ever enters service) would allow approximately 18 x 150s to go in the mid 2020s.