Final answer:
It's true that a variable displacement engine can shut down cylinders to save fuel, leveraging cylinder deactivation technology to reduce fuel consumption when full power isn't necessary.
Step-by-step explanation:
The statement that a variable displacement engine can shut down cylinders to save fuel is true. Variable displacement technology, also known as cylinder deactivation, allows an engine to automatically deactivate some of its cylinders when full power is not needed, such as during cruising or light load conditions. This reduces fuel consumption because fewer cylinders are burning fuel. In contrast, when more power is required, the engine reactivates the deactivated cylinders to deliver the full performance expected.
A gasoline engine typically burns less fuel at lower speeds. This principle is part of why technologies like variable displacement are beneficial—they capitalize on the variable needs of the driver. In addition, a cyclical process such as that employed by heat engines, including internal combustion engines, involves returning the system to its initial state at the end of every engine cycle, ensuring continuous operation.