normally in the manual they said
'do not switch off the engine immedietly after extended period of driving'
turbines run at high revolutions, so it generates heat.oil acts as a coolant for the turbine. while driving, the turbine gets hot. if engine is shut off immedietly, the hot turbine loses its coolant(oil flow) and...it might get spoiled, similar when you sprinkle water on your windscreen on a very hot day.
that's why turbo timers are for...to cool down the turbines
just take out the keys from the ignition switch while leave the engine running for about..a minute.
or to avoid accidentally switch off the engine after driving.
just sharing what i have in mind.