I can’t help myself here. Have experience designing and developing turbo spark ignition engines. I pioneered the early adoption. The concern over turbocharger durability is usually related to center section bearing wear due to lubrication coking. This happens when you shut down and induce a hot soak - frying the oil that remains in the cast iron center section. This abrasive substance kills the bearings, leaving the turbine and compressor to contact their respective housings. As pointed out by LVSteve, manufacturers don’t just hang a hair dryer on the side of the engine and call it quits. Think inconel exhaust valves, overplated bearings, forged pistons, and much much more. We ran numerous 100 hour test engines at 50% peak horsepower and 50% peak torque. At teardown we were looking for abnormal wear. Today’s engine control systems are incredibly good at keeping you safe.
The solution to the coking concern is synthetic oil with scheduled oil changes. I’ve personally viewed several failed turbochargers and invariably the bearings were failed. The beauty of a turbo engine is that it doesn’t recognize altitude performance degradation and, improved fuel efficiency if you stay out of boost. Once you step into it, the increased charge density usually requires a richer air/fuel ratio to kind of “suppress the flame front” and keep you out of detonation.
I think every good naturally aspirated engine deserves a turbocharger! Just my highly prejudiced opinion!
Tom H.
