Test results cold and after warmup @14V ~10min
3 New Bosch 0 332 019 103: cold 5.6V, 5.3V, 5.9V; hot 6.9V, 7.2V
Old EZK XXII: cold 6.3V cold, hot 7.7V
2 old relays 53 XXV and XXVI cold 7.3V and 7.4V, hot 8.8V and 8.9V. Holy shit.
These old 53ers would clearly disqualify in nowadays cars. At least for the engine control + fuel pump use.
Add some voltage drop across the wires, some ground shift while high-amp cranking, and some saturation voltage in the driver ASIC (anyone knows how much?)
And here we are in trouble very quickly.