Original alternators on all MBs but the 83, so hat means 20+ years and 235k on one, 12 years and 200k on the other. The 83's bosch rebuid was at about 160k.
The toyota has its original alt at 215k. The others are all OE, but thats not of interest, that is only 1500-160k for us right now in our fleet.
The BMW and integra were the only cars that we had to replace alternators at low mileage. The BMW had a diode go bad, the alternator worked, but the battery would drain if it was turned off... Dont know what the issue was with the integra, it jut didnt work.
JMH