1. What is the Wheel RPM Calculation?

The Wheel RPM calculation determines how many revolutions per minute a wheel makes at a given speed based on the tire circumference. This is important for vehicle tuning, gear ratio calculations, and performance analysis.

2. How Does the Calculator Work?

The calculator uses the Wheel RPM formula:

Where:

• \( RPM \) — Wheel revolutions per minute
• \( speed \) — Vehicle speed in miles per hour (mph)
• \( tire\_circ \) — Tire circumference in inches
• 336 — Conversion factor (combining miles to inches and hours to minutes)

Explanation: The formula converts vehicle speed to wheel rotation speed by accounting for how much distance the tire covers in one revolution.

3. Importance of Wheel RPM Calculation

Details: Knowing wheel RPM helps in gear ratio selection, transmission tuning, fuel efficiency calculations, and diagnosing drivetrain issues.

4. Using the Calculator

Tips: Enter speed in mph and tire circumference in inches. For accurate results, measure tire circumference with the vehicle's weight on it (loaded circumference).

5. Frequently Asked Questions (FAQ)

Q1: How do I measure tire circumference?
A: You can measure it directly by marking the tire and ground, rolling the vehicle one revolution, and measuring the distance. Or calculate from tire size: circumference = π × diameter.

Q2: Why is 336 the conversion factor?
A: It combines 5280 (feet per mile) × 12 (inches per foot) ÷ 60 (minutes per hour) = 1056, then divided by π (3.1416) ≈ 336.

Q3: Does this work for metric units?
A: No, this formula uses mph and inches. For km/h and mm, you would need a different conversion factor.

Q4: How does wheel RPM relate to engine RPM?
A: Engine RPM = Wheel RPM × final drive ratio × transmission gear ratio (for the current gear).

Q5: What's a typical wheel RPM range?
A: At 60 mph with 26-inch diameter tires (~81.7" circumference), wheel RPM is about 740 rpm.