Captain iOS BeeSwarm

Will any R211 cars have propulsion systems other than the Alstom OPTONIX, similarly to how some R160s have Siemens rather than Alstom? Also, why did the MTA order siemens propulsion cars to begin with?

Also just wondering, can the R211s or other NTTs last 50+ years in revenue service like the R32s managed to or is it not possible to due to certain factors? I'm not trying to be biased towards any subway car with this question, just curious.

Will the R211Ts be retired after 10 years like the R110As and R110Bs were, or will they continue to run in regular service until it is time to retire the R211s? 

Just wondering, when 2 NTT car types that aren't compatible are coupled together, what does the TOD display? What would happen if a R160 and R211 were coupled?