What lubricates and cools the turbo-charger bearing?

The use of the engine oil to lubricate and cool the turbocharger bearing is essential for maintaining the performance and longevity of the turbocharger. Engine oil is circulated through the engine components, including the turbocharger, under pressure, providing both lubrication and cooling. This ensures that the turbocharger operates efficiently, as it can reach high temperatures due to the exhaust gases that power it.

By utilizing the engine oil, the turbocharger benefits from the same high-quality lubrication that protects other vital engine components, promoting a coherent and efficient system. This integration is crucial because it simplifies the engine design and reduces the need for additional separate lubrication systems, which can add complexity and weight.

In comparison, while other options suggest alternative lubrication methods, they do not reflect the standard practice in most engines where the engine oil serves multiple roles, including those for the turbocharger.