What is the most efficient RPM to drive at?

When it comes to driving efficiency, the question of the most efficient RPM, or revolutions per minute, arises. What exactly is the optimal RPM range for maximizing fuel economy and minimizing wear and tear on the engine? Is it better to stay at a low RPM, say below 2000, or should we aim for a mid-range, perhaps around 2500 to 3000 RPM? Or could it be more efficient to push the engine harder, operating in the 3500 to 4000 RPM range? Understanding the impact of RPM on fuel consumption, engine performance, and longevity is crucial for any driver looking to optimize their vehicle's performance. So, what is the most efficient RPM to drive at, and how can we achieve it?