How does the eco-roll mode in commercial vehicles contribute to the reduction of fuel consumption?

Eco-roll mode in commercial vehicles reduces fuel consumption by making the most of the vehicle’s kinetic energy. When eco-roll is activated, the drivetrain is decoupled, allowing the vehicle to roll or coast with minimal resistance rather than continue to power the engine. This reduces unnecessary fuel use, especially on gentle downhill sections or even level terrain. The key idea is that instead of using the engine or brakes, the vehicle’s own motion is used as much as possible, which saves fuel. Increasing engine braking or reducing the rolling phase would have the opposite effect and could increase fuel consumption. So, utilizing the vehicle’s kinetic energy is the main benefit of eco-roll mode, which is why answer 1 is correct.