Gear Ratio

The gear ratio is the number of revolutions the engine makes compared to the number of revolutions of the transmission gear. When in lower gears, like 1st gear, the ratio is high(e.g. 3:1). This means that for every 3 revolutions the engine makes, the transmission(leading to the driveshaft and differential). A gear ratio can also be measured as the number of teeth on two different gears. If the moving gear has 15 teeth, and the other(called the idler) has 35 teeth, the gear ratio would be 3:7. For every 3 revolutions the smaller gear (called the pinion) makes, the idler gear makes 7.