Final answer:
The benefit of the 2021 NV200's engine speed dropping while at cruising speed is improved fuel economy and reduced emissions.
Step-by-step explanation:
The benefit of the 2021 NV200's engine speed dropping while the vehicle is at cruising speed is improved fuel economy and reduced CO₂ emissions. Transmission technologies like 7+ speeds, dual clutch transmissions (DCTs), and continuously variable transmissions (CVTs) help optimize the engine's performance and maintain a constant speed, leading to better fuel efficiency. When the engine speed drops, the throttle releases less gas, resulting in less fuel consumption and lower emissions.