Originally Posted by Fritzo
I agree about the turbo- older turbo designs didn't get any oil for the first several seconds of the engine running, giving them a lower life span. However, a modern turbo design would normally compensate for that.
At idle there's not really enough exhaust pressure to bring the turbine up to any meaningful speed though.
The problem with older turbos as I've experienced it wasn't so much a lack of start-up lube, it was oil coking from heat soak when people didn't let the car cool down for a minute or so after driving. The oil would coke and you'd get crystallized particles in the bearing, which scored the shaft and seals causing problems or blocked the oil inlet passages.
Modern turbos have cooling jackets around the bearing and either use electric pumps or thermosiphon to keep coolant circulating after the engine shuts off. This prevents the coking issue and is really what allows modern turbos to last longer.