Which of the following are smart driving techniques that can save fuel?

Easing off the throttle is indeed a smart driving technique that can significantly save fuel. This method involves reducing the pressure on the accelerator, which leads to a smoother and more gradual increase in speed rather than a rapid acceleration. When drivers ease off the throttle, the vehicle can operate at lower RPMs, allowing the engine to be more fuel-efficient as it consumes less fuel at lower speeds. This practice not only conserves fuel but also helps in minimizing wear and tear on the vehicle's mechanical components.

In contrast, methods such as accelerating rapidly from stops or maintaining high RPMs can lead to increased fuel consumption. Rapid accelerations demand more energy, resulting in increased fuel usage, while high engine RPMs typically indicate that the engine is working harder and consuming more fuel. Driving in the wrong gear can also result in inefficient fuel use since the engine may be overworked or under-utilized, leading to unnecessary fuel expenditure.