1. What is a Tire Conversion Calculator Comparison?

Definition: This calculator compares tire sizes by calculating the ratio between new and old tire diameters and determining the resulting speedometer error.

Purpose: It helps vehicle owners understand how changing tire sizes will affect their speedometer accuracy and vehicle performance.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Ratio \) — Dimensionless comparison value
• \( New\ Diameter \) — Diameter of new tire (mm)
• \( Old\ Diameter \) — Diameter of original tire (mm)

Explanation: A ratio of 1 means no change. Values > 1 mean larger tires (speedometer reads slower than actual speed). Values < 1 mean smaller tires (speedometer reads faster than actual speed).

3. Importance of Tire Size Comparison

Details: Proper tire sizing ensures accurate speedometer readings, maintains proper gearing, and prevents rubbing or clearance issues.

4. Using the Calculator

Tips: Enter both tire diameters in millimeters (can be calculated from tire size markings). The calculator will show the ratio and speedometer error percentage.

5. Frequently Asked Questions (FAQ)

Q1: How do I find my tire diameter?
A: Use a tire size calculator or the formula: (Width * Aspect Ratio / 100 * 2) + (Wheel Diameter * 25.4)

Q2: What's considered an acceptable ratio?
A: Generally within ±3% (0.97-1.03 ratio) is acceptable for most vehicles.

Q3: How does this affect my odometer?
A: The odometer will be off by the same percentage as the speedometer.

Q4: Will this affect my vehicle's performance?
A: Larger tires may reduce acceleration but improve fuel efficiency at highway speeds. Smaller tires have the opposite effect.

Q5: How can I correct speedometer error?
A: Many modern vehicles can be recalibrated via the OBD-II port. Some require mechanical speedometer gear changes.