1. What is Tire Rev Per Mile?

Tire revolutions per mile is a measurement that indicates how many times a tire rotates to cover one mile of distance. This calculation is important for vehicle speedometer calibration, gear ratio selection, and fuel efficiency calculations.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( Revs \) — Revolutions per mile
• \( Diameter \) — Tire diameter in inches

Explanation: The constant 20168 represents the number of inches in a mile (63,360) divided by π (3.14159), which converts circumference measurements to diameter-based calculations.

3. Importance of Revs Per Mile Calculation

Details: Knowing your tire's revolutions per mile is crucial for accurate speedometer readings, proper transmission shifting, optimizing fuel efficiency, and selecting appropriate gear ratios for performance applications.

4. Using the Calculator

Tips: Enter the tire diameter in inches. Measure from the ground to the top of the tire when properly inflated and under load for most accurate results.

5. Frequently Asked Questions (FAQ)

Q1: How do I measure tire diameter accurately?
A: The most accurate method is to measure from the ground to the top of the tire with the vehicle's weight on it and proper inflation pressure.

Q2: Why does revs per mile matter for my vehicle?
A: It affects speedometer accuracy, odometer readings, transmission shift points, and ABS/traction control systems in modern vehicles.

Q3: How much do tire revs change with wear?
A: As tires wear down, the diameter decreases slightly, which increases revolutions per mile. A 1/8" wear can change revs by approximately 5-8 per mile.

Q4: Does inflation pressure affect revs per mile?
A: Yes, underinflated tires have a slightly smaller effective diameter, which increases revolutions per mile slightly.

Q5: How does this affect fuel economy calculations?
A: If your actual tire revs differ from what the vehicle computer expects, your fuel economy readings may be inaccurate.