Anyway, the 90 seating car is very profitable with the faster engines available: The Br
While the 90 seater H-Trans (Passagierwagen) is profitable. I find the 48 seater SingCo (PrPersonenwagen) car to generally be a better choice.
@80% average load, in 1926 a BR39 can pull 7 SingCo, 4 tile length, total capacity 336, 0.133 cents/passenger-mile profit.
A BR01 can pull 6 H-Trans, 4 length, capacity 540, 0.098 cents/passenger-mile.
BR01-H-Trans hauls 60% more passengers but profit/passenger is only 75% that of the BR39-SingCo convoi. Profit/convoi is 20% better. It only makes sense to use the BR01 convoi when you'd otherwise need to add more infrastructure (track/station tiles with monthly maintenance) to handle adding more BR39 convois to move all the available passengers.
With the speed bonus base speed increasing, by 1938 BR39-SingCo is down to 0.117 c/pm, but BR01-H-Trans is at 0.077, Only 66% of the profit now.
By 1952, SingCo 0.104, H-Trans 0.060, 57%.
But 1952 opens up the Empire-Osaka (TPPassagierwagen) car. BR01 pulling 5 Empire-Osaka, 4 length, 810 capacity, 0.142 c/pm. H-Trans and SingCo obsolete, can't compete with that profit. Br39, 2*Empire-Osaka, 2 length, 324, 0.123 also available for lesser capacity routes.
Reducing the running cost of the H-Trans from 880 to 700 would let it compete with the SingCo more effectively. SingCo still slightly ahead.
Also, why not extend the SingCo retire date to 1952? Doesn't make sense to have that one year gap IMHO.