What is final drive ratio

These gear sets are better suited for towing and hauling heavy loads. Generally, a lower final drive ratio will lead to less torque at the wheels but a higher top speed. This means:. A higher final drive ratio will result in more torque at the wheels but a lower top speed. Since torque is what helps the vehicle accelerate, a higher final drive ratio will offer better acceleration.

The reason a higher ratio will help accelerate a car faster is because the engine can spin up faster and creating more leverage to turn the wheels. The straightforward way to calculate the Final Drive Ratio is to divide the number of teeth on the ring gear by the number of teeth on the pinion gear.

For example, if the ring gear has 30 teeth and the pinion has 10, take the number 30 and divide by 10 to get the ratio of This means the pinion must rotate three times to make the ring gear rotate once, which in turn rotates the tire once. If you are looking for an online tool to calculate your Final Drive ratio, you can find one here.

GVWR: The safe weight maximum a vehicle can operate with, including payload. Payload Capacity: The maximum amount of cargo weight that can be added to a vehicle. Basically, it is the ratio of the gear's angular velocity that gives the input to output ratio.

You can easily calculate the final drive ratio directly from the number of teeth on the crown-wheel and pinion. The manufacturers define the final drive ratio and mechanical ratio in such a way that it results in a number that forms an ideal association.

Let's refer to the diagram above. Let's assume that the vehicle is traveling in the 4th gear whose gear-ratio is , which means the gearbox input is equal to its output. In the 4th gear, to rotate the wheels by one rotation, the engine needs to rotate the pinion 3. This means the engine itself needs to rotate 3. Thus, in this case, the engine turns 3. The engine speed always reduces by the final ratio to rotate the wheels by one turn.

Similarly, in the 1st gear, whose ratio is 3. Hence, this ratio is known as the final drive ratio. Generally, the Automobile drive train has two or more zones where the manufacturers use the gearing.

One is in the gearbox, while the other is in the axle. Thus, it helps to deliver a great combination of the vehicle speed and torque at the wheels. Besides, the modern-day transmissions also employ the built-in differential gearing system. It also contains the Final-Drive that provides further speed reduction at the wheels. The problem is that changing individual ratios in a gearbox can be a tricky mess. And changing an entire gearbox can be prohibitively expensive. But if you want better acceleration or more top speed , there is an easier solution to your problem: Change your final drive ratio.

The gears within your transmission aren't the only gears in a car. There's also a gear in the rear differential that puts the power to the ground. This is known as the final drive. And by fitting a shorter final drive you can achieve better acceleration, since you can increase the amount of torque to the wheels, or you can fit a taller one and increase your top speed.