When cleaning grades, which of the following actions is advisable?

Keeping your engine RPM in the proper operating range is advisable when cleaning grades because it ensures that the vehicle operates efficiently and effectively. When navigating grades, particularly steep inclines or declines, maintaining the correct RPM range allows for optimal power and control. This balance is crucial for preventing stalling on hills or losing traction when going downhill.

Proper RPM management helps to avoid excessive strain on the engine, which can lead to overheating or damage. By staying within the recommended RPM range, you also enhance the vehicle's braking capabilities, particularly when descending steep grades, ensuring that you can respond effectively to changing terrain conditions.

Maintaining a steady speed is important in specific circumstances, but it needs to be calibrated with engine RPM for efficiency. Staying in the far left lane and slowing down excessively do not support this effective operation and could be risk factors on grades.