What engine feature aids in the overall efficiency of the Turbo Compound setup?

The correct choice focuses on enhanced heat recovery as a vital feature that contributes to the overall efficiency of a Turbo Compound setup. In this context, a Turbo Compound system typically captures excess exhaust energy that would otherwise be wasted. This energy is then used to drive an additional turbine connected to the crankshaft, which helps to recover lost energy and convert it into usable mechanical energy.

This process improves the overall efficiency of the engine by making better use of the energy generated during combustion. By maximizing the utilization of exhaust heat, enhanced heat recovery contributes to reduced fuel consumption and lower emissions, making the engine more efficient overall. This feature is particularly beneficial in larger engines, where the potential for heat recovery is greater, thus promoting overall efficiency and performance while maintaining or improving output.

In contrast, while other features may play a role in engine performance, they do not directly address the efficient conversion of excess heat into usable energy in the same manner as enhanced heat recovery.