(13 Aug 2020, 9:10 pm)streetdeckfan wrote I personally don't think it's an issue with the engine itself, but the gearing. It's clearly not geared for higher speeds. Like you say it's great at stop/start routes, but most of the X21 isn't stop start. Even the parts that aren't motorway are still fast A roads which means higher revs, and more wear on the engine.Agree on the statement for stop / start routes. Wouldn't surprise me if we see "green shoots of recovery" economic wise that GoNE will order them for the 56 & Cobalts with the B9TLs cascaded either within Go North East or nationally. They're perfect for both routes and would reduce the fuel bill massively.
The same can be said for parts of the X45/46, so it'll be interesting to see how well they cope on there.
Perhaps won't be for another 2-3 year at least and economic wise, I think it's just a matter of taking it day by day for all operators at the moment.