My game is now in 2051. I have a realistic train network, and two 'experimental' monorail and maglev networks. I've gone through replacing my SH'30s on the rail network with SH'40s, even with short feeder consists, then T.I.M.s with AsiaStars, even though my map isn't in Asia (renaming them to Eurostar solved that problem).
But now my rail network is breaking down entirely with SHs at 75% and Eurostars at 59% for no reason, as if all those trains were running Microsoft Windows.
This game can't continue. I sort of assumed that the game allowed any option for operating normal railways. Even an ugly one, like AsiaStars for hauling grain.I have searched the web, and found that I need to enable the advanced setting and then use "resetengines" console command to get good trains back. I started a new game where engines would not expire, but now all of them are available at all times in depots for purchase, making lists quite cluttered. If I sort them by power, I still need to scroll down to pick cargo cars.
So why not the old way: keeping only engines which are in use and for which the player probably has autorenew contracts for? Sure some 'locomotive works' would be willing to build and sell them for me, no? I've a billion pounds ready, which go a long way in this game for buying trains.
Try to tell you car dealer that you're entitled to a completely new version of your car even while there current version is two model cycles newer. Alternatively write a patch to add a 3rd option the 'vehicles never expire' option. Not sure the behaviour your describe is a desirable one, though, and worth the complication.