3000 RPM is exactly the middle of the range of a standard consumer car #engine. And for combustion engines it's where they are the most efficient in terms of horsepower over fuel consumption. You don't want to put any load, even moderate acceleration on your engine at low #RPM, which is basically idling.
See. You want to accelerate, ok, moderately, but still to accelerate. You need some amount of energy for that. The energy comes from burning fuel, nothing else. So, to accelerate at a certain rate you need some volume of fuel. Now, lets shift gears the way so the engine keeps low RPM, let's say 1500 RPM, the half of 3000 to simplify the math. At 1500 it will make half the strokes per second than at 3000. But you still have to pour the same amount of fuel per second to keep up with the acceleration. So the engine is forced to burn twice as much fuel per stroke. That means more compression in the cylinder, more stress on moving parts, more heat. And more heat means more energy lost into the environment. So no, accelerating even moderately at low RPM is not efficient. That's why automatic #transmissions are configured to rev up when #acceleration is requested.
3000 RPM is louder, yes. But in this mode the engine mostly blows air through its cylinders if the load is moderate. It produces relatively less heat because it burns less fuel per stroke. Also when the transmission is on lower gear the engine endures less stress.
So, no, it's not a scream. It's a song :)
PS: Very high RPM, like at 6000 is also not most efficient but it's used for max #horsepower the engine can produce when needed (Sports Mode).
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