1. What is Axle Gear Ratio?

The axle gear ratio is the number of turns the driveshaft makes compared to one complete turn of the axle. It's a crucial specification that affects vehicle performance, fuel economy, and towing capacity.

2. How Does the Calculator Work?

The calculator uses the simple gear ratio formula:

Where:

• \( teeth_{driven} \) — Number of teeth on the driven (ring) gear
• \( teeth_{driver} \) — Number of teeth on the driver (pinion) gear

Explanation: The ratio represents how many times the driveshaft must rotate to turn the wheels once.

3. Importance of Gear Ratio

Details: The gear ratio affects acceleration, top speed, fuel efficiency, and towing capacity. Lower ratios (e.g., 3.08:1) are better for highway cruising, while higher ratios (e.g., 4.10:1) improve acceleration and towing.

4. Using the Calculator

Tips: Count the teeth on both gears carefully. The driven gear is typically the larger ring gear, while the driver gear is the smaller pinion gear.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical gear ratio for passenger cars?
A: Most modern passenger cars have ratios between 2.5:1 and 3.5:1.

Q2: How does gear ratio affect fuel economy?
A: Higher ratios (numerically lower) generally provide better highway fuel economy by allowing lower engine RPM at cruising speeds.

Q3: What gear ratio is best for towing?
A: Vehicles used for towing typically benefit from lower gear ratios (numerically higher) like 3.73:1 or 4.10:1 for better low-end torque.

Q4: Can I change my vehicle's gear ratio?
A: Yes, but it requires replacing the ring and pinion gears in the differential and may affect speedometer accuracy and transmission shifting.

Q5: How does gear ratio relate to tire size?
A: Larger tires effectively create a higher gear ratio, which is why re-gearing is often recommended with significant tire size changes.