Originally Posted by
Digger
Turbo's spin inside what is called an oil bearing, no mechanical bearing manufactured today would last at the speed these turbo spin. Full synthetic or not, running a turbo on the highway and shutting it down hot can cause the lubricant to crystalize and eventually lead to turbo failure. When you drive a car with a turbo a good habit to develop is to let the engine idle for at least 30 seconds before turning the car off.
Most people don't live on the freeway off ramp and they get slowed down and pretty well cooled down on the side streets leading home. For most turbo owners the most likely cause for early turbo failure is that sometime in its life the car got the wrong kind of oil. If you don't change the oil yourself and you weren't there to watch, you don't know for certain that the oil that came out, is the same kind that went back in. If you're not there when the work is done, you aren't there to spot a rip off, or an honest mistake, but if your oil change cost less than expected when you go to pick the car up, you probably got filled with semi and not full synthetic. This would be an honest mistake, the real mistake comes when you drive away happily accepting the lower price without questioning why.