Why Shifting Gears is a Thing
Many of those among us who are not naturally mechanically inclined have likely thought at some time or another, “why does a car have to have gears, anyway? Why can’t it just run without that weird little addition?”
Although in our modern age of automatic transmissions, the “inconvenience” of gear-shifting is not anything like it used to be (though you may be confused by the extra speeds on an automatic), it can still be a curiosity as to why multiple gears are necessary for a vehicle. Why is it important to be in the right gear when driving?
Being in the right gear is important to keep efficiency and performance of the vehicle at an optimum level. To perform best, an engine should stay rotating near the “sweet spot” of 2000 to 4000 rpms for torque. In order to keep it in this range, the gear ratio between the engine and tires needs to be changed based on the speed at which the wheel is turning.
How do gears in cars work?
If this still sounds confusing, imagine riding a bicycle with multiple gears. If you’re standing still and start pedaling with the bike in a high gear, it’s very difficult. You’re going to be expending a lot of energy to do so. It’s easier to start moving in a low gear. A car engine feels the same way.
However, as you start going faster, you’re going to be expending a lot of energy to keep on speeding up if you stay in that low gear. Imagine how fast your feet would be turning- that’s what the engine would be trying to do!
So by shifting to a higher gear ratio, the vehicle is able to keep increasing the rotation speed of the wheels while not having to turn at an astronomical rate. And now it’s not so difficult to move in a high gear because the vehicle already has the momentum built up.
Man, physics is weird.
Have you heard of CVT, or “Continuously Variable Transmission?” If so, you’re probably wondering: What’s the difference between automatic transmission and CVT?