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Final Drive Formula:
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The final drive ratio is the overall gear reduction between the engine and the wheels in a vehicle. It's calculated by multiplying the transmission gear ratio by the differential ratio, representing the total torque multiplication from engine to wheels.
The calculator uses the final drive formula:
Where:
Explanation: This calculation determines the complete gear reduction from engine RPM to wheel RPM, affecting acceleration, top speed, and fuel economy.
Details: The final drive ratio significantly impacts vehicle performance. Lower ratios provide better fuel economy and higher top speed, while higher ratios deliver quicker acceleration and better towing capacity.
Tips: Enter both gear ratio and differential ratio as positive numbers. Typical values range from 2.5 to 4.5 for differential ratios and vary by gear selection in the transmission.
Q1: How does final drive ratio affect performance?
A: Higher ratios provide better acceleration but lower top speed, while lower ratios offer higher top speed but slower acceleration.
Q2: What's a typical final drive ratio range?
A: Most passenger vehicles have final drive ratios between 2.5:1 and 4.5:1, with sports cars often having higher ratios for better acceleration.
Q3: Can I change my vehicle's final drive ratio?
A: Yes, by changing the differential gears, but this affects fuel economy, speedometer accuracy, and may require ECU recalibration.
Q4: How does final drive ratio relate to RPM at speed?
A: Higher final drive ratios result in higher engine RPM at any given speed, which can affect fuel consumption and engine wear.
Q5: What's the difference between gear ratio and final drive ratio?
A: Gear ratio refers to a specific transmission gear, while final drive ratio is the total reduction including both transmission and differential.