Quote Originally Posted by Peter-E36
Excellent, didn't know that! So that's why it has an electric water pump? And I thought they were just being awkward no harm in leaving it running a little bit though as you say.
Electric water pump reduces parasitci load on the engine increasing performance and efficiency.

It also reduces heat soke after the engine is shut down as it continues to circulate the coolant being powered off the battery.

Quote Originally Posted by Peter-E36
Actually, that takes care of cooling but what about lubrication? Would the turbos not be spinning dry when the engine is switched off still? Do they have an electric oil pump top? So many questions!! Interesting stuff to know though
Turbos are "spun" by exhaust gas. There is no exhaust gas when the engine is not running.
Oil pressure is maintained long enough for impellers to spool down.