1. What is the Wheel Size Speed Comparison?

The Wheel Size Speed Comparison calculates how changing your wheel diameter affects your vehicle's speed reading and actual speed. When you change wheel sizes, your speedometer may become inaccurate unless recalibrated.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Speed_{new} \) — Actual speed with new wheels (mph)
• \( Speed_{old} \) — Speedometer reading (mph)
• \( New_{dia} \) — Diameter of new wheels (inches)
• \( Old_{dia} \) — Diameter of original wheels (inches)

Explanation: Larger wheels cover more ground per revolution, making your actual speed higher than what your speedometer shows if not recalibrated.

3. Importance of Wheel Size Comparison

Details: Understanding this calculation helps ensure your speedometer remains accurate after wheel changes, preventing speeding tickets and maintaining proper vehicle operation.

4. Using the Calculator

Tips: Enter your current speed reading, original wheel diameter, and new wheel diameter. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: How accurate is this calculation?
A: It's mathematically precise for perfect circles, but real-world factors like tire pressure and wear may cause minor variations.

Q2: Does this affect odometer readings?
A: Yes, the same ratio applies - your odometer will under-report distance with larger wheels.

Q3: What if I change both wheel and tire size?
A: Use the total diameter (wheel + tire) for both old and new measurements.

Q4: How much difference is significant?
A: A 3% or greater difference typically requires speedometer recalibration.

Q5: Does this apply to all vehicles?
A: Yes, the principle applies to any wheeled vehicle, though implementation may vary by manufacturer.