Automotive & Engines

Basic

Gear Ratio

Ratio of driven to driving gear teeth.

Formula

GR = \frac{N_{out}}{N_{in}}

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Variables

GRGear ratio

N_{out}Driven gear teeth

N_{in}Drive gear teeth

Example

40 driven, 10 drive: GR = 4:1

Did You Know?

A low first gear (high ratio) multiplies torque for acceleration; overdrive gears below 1:1 save fuel at cruise.

automotive gear transmission

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