Why do we measure engine speed in RPM instead of cycles per second (Hertz)?

Question

My car idles around 600 RPM which is equal to about 10 cycles per second and redlines at around 6,000 RPM which is 100 cycles per second. This just seems like a more friendly scale to use. I am curious why we use RPM instead of Hertz to measure engine speeds.

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Answer 1

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