If you’ve ever run up a slope, you know how daunting of a task it can be. If you were to expend all your energy in pursuit of reaching the top as fast as possible, chances are you would run out of breath midway and be forced to stop. However, if you were to expend your energy in overcoming the force that gravity exerts on you, you would eventually make it to the top, though not as fast as you may have wished. The situation demands endurance over speed; running slowly and steadily is the only sensible option.
Now, consider a less tiresome scenario. If you were asked to run downhill, you would happily agree. With gravity on your side, you’d reach the bottom of the slope faster than it would take to read this sentence.
However, while running downhill, we often tend to lose control of ourselves and actively try to slow down in the face of the risk of tumbling down like a rolling stone. Is this a matter of endurance then? No. In fact, we’re over equipped with endurance for such a task. However, excess speed can cause us to lose control and end up as a messy bag of public humiliation and broken bones.
Compare this to running on the beach. It takes less endurance, as one doesn’t have to worry about overcoming gravitational forces or exercising restraint to prevent rolling and slipping. As you gather pace, your sheer momentum carries you on, and you don’t have to expend as much energy to keep moving quickly.
The transmission of a car does exactly what our good sense does for us while running: it strikes a balance between the torque (endurance) and speed (the cause of public humiliation in the event of an uncontrolled descent while running) by a change of gears.
Gearboxes enable the generation of more torque at lower gears and more speed at higher gears, and one must shift gears, depending on the need for speed or torque.
A car moving uphill or downhill should ideally be in a lower gear for more torque and more speed control, respectively. However, upon reaching cruising speeds, using the same amount of energy as one would use in more endurance-oriented situations is not only wasteful, but detrimental to the engine’s integrity as well. This is why it’s necessary to shift into a higher gear to reach higher speeds.
The act of continually fidgeting with a lever, as one scuttles along the motorway suddenly isn’t as meaningless as it seems to be. While certainly not meaningless, it’s definitely annoying and tiring, leading us to the next question: