What is the effect of increased viscosity of added oil on engine performance?

In the context of engine performance, an increase in oil viscosity can indeed have significant effects. When oil viscosity is too high, it can lead to several drawbacks in engine functionality. High viscosity oil tends to be thicker, which can create more resistance as it flows through the engine components. This increased resistance may hinder the efficient circulation of the oil, leading to inadequate lubrication of critical engine parts.

Efficient lubrication is essential for minimizing friction and wear, as well as for maintaining optimal engine temperatures. If the oil is too viscous, it may not reach all necessary areas within the engine effectively or quickly enough, potentially leading to various performance issues, including increased frictional losses and overheating. Over time, these factors can result in reduced overall engine efficiency and decreased fuel economy.

In summary, while the option highlights viscosity being "too high," the reality is that excessively viscous oil can adversely affect engine performance by impairing lubrication, increasing friction, and ultimately hindering efficiency.