Okay here is how i see it

Your engine has numerous parasetic loads on it these being water pump, oil pump, powersteering pump, AC compressor, belt drag, and a few others

Now the water pump is a huge compramise as it is designed to cool the engine at idle in a traffic jam in a hot climate after possibly heavy driving so it needs a real good flow at idle, now you then take the same pump and cruise along a motorway in norway with the engine running considerably faster and a huge amount more cooling from cold air and more airflow so then the water pump is running far harder than needed.

The same could be said to some extent to the oil pump.

Now dump the oil pump and water pump and drive them electrically.

Get in your car turn the key, the engine does not start but your lub oil pump starts and runs for 5 seconds pre lubing your bearings then the engine starts with nice oiled bearings and runs, the water pump is still stopped and the engine climbs in operating temperature far faster giving you better combustion and now you drive along the motorway in motorway and the water pump matchs its speed to engine and ten miles later you are in arazonia desert traffic jam your engine is idleing but the water pump is flat out you then move along a bit. You stop at the traffic lights and decide to drag race off the lights you get full engine power as your generator will switch off and your pumps and extras will run for a short period off the battery supply.

now that as far i could see would be an advantage, the dump the water pump modifcation is already very common in racing saloons.

from my point of view i think 42 volts is good