Eli5: how can you roll start a manual vehicle but not an automatic vehicle?
In: Other
A manual has a clutch, which is a rigid coupling. The motion of the wheels is transmitted even at low speeds, there is no slip.
An automatic uses a torque converter, which is a fluid coupling. There has to be significant motion for it to transmit enough energy. It slips constantly.
Imagine you have a fan (the engine) that you want to spin. A manual would be equivalent to you rotating the blade with your hands. An automatic would be like you trying to rotate the blade by gently blowing on it. Since the fan has a lot of resistance (engine compression and friction), gently blowing on it won’t cause it to spin. You’d have to use a leaf blower.
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