165/166s especially are known for having knackered engines, surely now would be a good time to look a re-engine them with more modern diesel engines, hybrids or looking a fitting exhaust emission reduction technology.
I believe Chiltern are to trial replacement of engines on a 165 soon (or it may have been a 168). If I recall correctly, the new engine raft would include batteries making it a hybrid similar to the batch of hybrid class 230s for Wrexham-Bidston. Something similar was proposed for the class 175s by the
ROSCO» who were keen to get them retained by the Wales & Borders franchise.
I believe there are already standards for seat pitch, etc; part of the issue there is that some of the older, softer seats conform less to modern safety standards
Not sure about seat pitch (I believe that's coming in the next version) but the Rail Delivery Group's Key Train Requirements (KTR) document does offer standards for things like coupling to other units and provision of toilets. However, it is so often ignored that I wonder whether it's worth the paper it is written on. For example Northern's class 195 CAF Civity
DMUs▸ apparently are unable to couple to anything else with the gangway-fitted class 196s requiring a different coupling due to the end gangways. I'm not sure if the TfW 197s will be able to couple to 196s or not. Also, the KTR spec for inter-urban and intercity services is a maximum of 85 seats per toilet, the 2-car TfW class 197s (which TfW intend to use on long-distance journeys, including some over 5hrs) will have 116 seats with just one toilet. We have some of the standards but they are ignored, which is why I said that they need to be mandatory standards rather than advisory as the KTR is.
Yet the modern rolling stock such as IETs▸ , Electrostars are often complained for being too hard? We need a standard set across all services, minimum leg room, seat comfort, lighting brightness.
I believe leg room is treated as a component of seat comfort in the new standard being developed which gives a single numeric score telling operators, politicians etc. exactly how comfortable the train is. At present, this new system is just a research paper, but it's findings are apparently going to be incorporated in version 6 of the KTR when it is published.