What are the advantages of using variable turbine geometry (VTG)?

Variable turbine geometry (VTG) is a significant advancement in turbocharger design that enhances performance, primarily by allowing for better airflow control. The correct choice highlights how VTG systems can adjust the geometry of the turbine to optimize airflow based on engine operating conditions. This adaptability leads to improved efficiency at various speeds and loads.

When the engine is under heavy load or during acceleration, the turbine vanes can be adjusted to a more open position, which enhances airflow and increases performance. Conversely, when the engine is at lower speeds, the vanes can close to optimize exhaust flow, improving responsiveness and reducing turbo lag. This dynamic adjustment is key to maximizing the efficiency of the gas turbine across a range of operating scenarios.

This ability to control airflow directly contributes to better fuel efficiency and performance, making VTG a valuable feature in modern turbine designs. The other choices, while related to turbine design, do not accurately capture the primary benefits of variable turbine geometry.