Eli5: How does changing gears in cars enable them to travel faster compared to using the lower gears at the rpm?

Question

Me monkey brain tried to do a google search on my own… me monkey brain didn’t understood a thing…me monkey brain need help

In: 1

Answer 1

If the wheels go double the speed, then the engine must go double the speed. Going from 10 to 50 mph will take your engine from 2,000 to 10,000 rpm. If that doesn’t blow it up, it will run very inefficiently. So we use gears to allow the engine to run slower when the wheels are moving faster, and so save the engine.