Just an FYI.
Today's turbochargers use water cooled housings, which helps to reduce coking.
However, the water cooling does not eliminate coking, as the turbine hot side is still red hot, as are the seals, and the shaft is still welded to the turbine. The shaft transfers heat right into the hot side seals and bearing(s) . It's not unusual for a turbine to be 1650 degrees F and the shaft a few degrees less.
What is different is the design of modern turbochargers. They are designed to operate properly with some coke buildup and are tolerant of it.
This is why people can "get away" with using lower quality oils on turbocharged engines without failures. However, at some point, the use of inferior oils coupled with high temperatures will result in significant buildup. Probably to the point of failure. Put another way, "that guy" who claims to use non synthetic with great results is likely unaware of the condition of the turbocharger.
Please use a quality synthetic in your turbocharged gasoline engine, AND change it regularly. It eliminates many potential problems.
NOTE: many diesel engines have EGT's that do not exceed 1200 deg F on a regular basis and larger diesel engines do not get the turbochargers anywhere near as hot as a high performance gas engine. Plus diesel engines have downright cool EGT's under light loads due to excess air. This lowers stress on diesel turbochargers.
Today's turbochargers use water cooled housings, which helps to reduce coking.
However, the water cooling does not eliminate coking, as the turbine hot side is still red hot, as are the seals, and the shaft is still welded to the turbine. The shaft transfers heat right into the hot side seals and bearing(s) . It's not unusual for a turbine to be 1650 degrees F and the shaft a few degrees less.
What is different is the design of modern turbochargers. They are designed to operate properly with some coke buildup and are tolerant of it.
This is why people can "get away" with using lower quality oils on turbocharged engines without failures. However, at some point, the use of inferior oils coupled with high temperatures will result in significant buildup. Probably to the point of failure. Put another way, "that guy" who claims to use non synthetic with great results is likely unaware of the condition of the turbocharger.
Please use a quality synthetic in your turbocharged gasoline engine, AND change it regularly. It eliminates many potential problems.
NOTE: many diesel engines have EGT's that do not exceed 1200 deg F on a regular basis and larger diesel engines do not get the turbochargers anywhere near as hot as a high performance gas engine. Plus diesel engines have downright cool EGT's under light loads due to excess air. This lowers stress on diesel turbochargers.
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