What makes an engine run better? What if the fuel / air mix os not right? How are electronics changing cars? these are so much fun to study.
Even engines like you say...there are lots of great internal combustion engines, from little four cylinders to big V-8's. They are best at high RPM. But electric cars are coming, and their electric motors run best at zero or low speeds, since the impellers have the most torque at zero speed. See the link below.
Study engineering, and this can be the stuff that you fix over time!
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