What does "stall speed" refer to in manual transmissions?

"Stall speed" refers specifically to the engine RPM at which the engine can no longer produce enough power to overcome the load imposed by the vehicle and comes to a halt, meaning the vehicle does not move despite the engine running. This concept is particularly relevant in manual transmissions when the vehicle is in gear and the clutch is engaged, as the vehicle will not start to move until the engine is revved to a speed that exceeds this stall RPM.

Understanding stall speed is crucial for drivers, especially when starting from a complete stop or when attempting to execute maneuvers such as hill starts, where the vehicle may need sufficient RPM to prevent stalling. The other options do not accurately capture this concept; for instance, maximum speed refers to a vehicle's potential speed, while effective gear shifting involves different RPM parameters entirely.