On manual cars, Why can’t a car start in a higher gear?

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As the title says, I know that different shifts mean different gear sizes bein used, but I don’t understand why it makes you unable to start moving the car. I have been able to start a couple of cars on the 2nd shift as an experiment and I understand that I could damage the car and I do it just once for testing purposes but I don’t understand why I cannot do so on other shifts. To clarify, I mean start as in start moving the car and not just turning the car on. Thanks

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46 Answers

Anonymous 0 Comments

Are you familiar with levers?

Put two bits of wood on the ground, one short, one really really long. Lift the short one from one end. Now do the same with the long one. The short one is easier right? The long lever has all that extra weight to lift and you’re so far from the axis of rotation. But as the lever gets more upright, it becomes a little easier right?

Gears are like round levers. The bigger the gear, the more torque (angular force) it takes to move them. When you start a car in high gear, you are trying to lift the long lever with an engine designed to only lift the small one from zero. You physically don’t have enough torque to move the higher gears. However at high speed, you don’t need as much torque because you’ve only got to “lift” the difference in distance between the levers, not the full from zero.

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