1. What is Tire Revolution Per Mile?

The Tire Revolution Per Mile calculation determines how many times a tire rotates to cover one mile. This measurement is important for speedometer calibration, gear ratio calculations, and vehicle performance tuning.

2. How Does the Calculator Work?

The calculator uses the following formula:

Where:

• \( Revs \) — Revolutions per mile
• \( Diameter \) — Tire diameter in inches
• 20168 — Constant representing inches in a mile (5280 feet × 12 inches)

Explanation: The formula calculates how many tire rotations are needed to cover the distance of one mile (63,360 inches) based on the tire's circumference.

3. Importance of Tire Revolution Calculation

Details: Knowing your tire's revolutions per mile is essential for accurate speedometer readings, proper transmission shifting, and optimizing fuel efficiency when changing tire sizes.

4. Using the Calculator

Tips: Measure your tire's overall diameter in inches (from ground to top of tire when properly inflated and under load) and enter it in the calculator.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure my tire diameter?
A: The most accurate method is to measure from the ground to the top of the tire when the vehicle is at normal ride height with proper inflation.

Q2: Why does tire size affect revolutions per mile?
A: Larger tires have greater circumference, so they need fewer rotations to cover a mile. Smaller tires rotate more times to cover the same distance.

Q3: How does this affect my speedometer?
A: If you change tire sizes without recalibrating, your speedometer will show incorrect speed (faster with smaller tires, slower with larger tires).

Q4: What's a typical revolutions per mile value?
A: Most passenger vehicles have tires that rotate between 700-900 times per mile, depending on tire size.

Q5: Does tire wear affect revolutions per mile?
A: Yes, as tires wear down, their diameter decreases slightly, increasing revolutions per mile (typically 1-2% over the tire's life).