1. What is the Effective Gear Ratio?

The effective gear ratio is the product of the gear ratio and overdrive ratio. It represents the actual ratio that accounts for both the gear reduction and any overdrive in the transmission system.

2. How Does the Calculator Work?

The calculator uses the effective ratio formula:

Where:

• Gear Ratio — The ratio of the gear set (dimensionless)
• Overdrive Ratio — The ratio of the overdrive unit (dimensionless)

Explanation: The equation multiplies the gear ratio by the overdrive ratio to determine the overall effective ratio that the engine experiences.

3. Importance of Effective Ratio Calculation

Details: Calculating the effective ratio is crucial for understanding vehicle performance, fuel efficiency, and engine RPM at different speeds. It helps in transmission tuning and gear selection.

4. Using the Calculator

Tips: Enter both the gear ratio and overdrive ratio as positive numbers. Both values must be greater than zero for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a typical overdrive ratio?
A: Most overdrive ratios range between 0.6 to 0.8, meaning they reduce engine RPM by 20-40% compared to direct drive.

Q2: How does effective ratio affect performance?
A: Lower effective ratios provide better acceleration but higher RPM at cruising speed, while higher ratios improve fuel efficiency at highway speeds.

Q3: What's the difference between gear ratio and effective ratio?
A: Gear ratio refers to a single gear set, while effective ratio accounts for all reduction/multiplication in the drivetrain including overdrive.

Q4: Can effective ratio be less than 1?
A: Yes, with sufficient overdrive, the effective ratio can be less than 1, meaning the output shaft spins faster than the input.

Q5: How does this relate to final drive ratio?
A: Final drive ratio is another multiplication factor that would be included in the complete drivetrain ratio calculation.