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Wheel Tire Speed Formula:
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The Wheel Tire Speed calculation determines the vehicle speed based on the engine RPM and tire circumference. This is useful for gear ratio calculations, performance tuning, and verifying speedometer accuracy.
The calculator uses the formula:
Where:
Explanation: The formula converts rotational speed (RPM) to linear speed (mph) using the tire's circumference and appropriate unit conversion factors.
Details: Accurate speed calculation is important for gear ratio selection, transmission tuning, speedometer calibration, and performance optimization in vehicles.
Tips: Enter RPM (typically between 500-8000 for most vehicles) and tire circumference in inches. Measure tire circumference by marking the ground and rolling the tire one complete revolution, or calculate from tire size specifications.
Q1: How do I find my tire circumference?
A: You can measure it directly by rolling the tire one revolution, or calculate it using the tire size numbers (e.g., 225/45R17) with online calculators.
Q2: Why is the conversion factor 336?
A: The factor 336 combines conversions from inches to miles (63360), minutes to hours (60), and simplifies the formula (63360/60/π ≈ 336).
Q3: Does this account for tire slip or deformation?
A: No, this is a theoretical calculation assuming perfect traction and no tire deformation. Actual speed may vary slightly.
Q4: Can I use this for different gear ratios?
A: This calculates final speed based on input RPM. For different gears, you'll need to account for the gear ratio between the engine and wheels.
Q5: How accurate is this calculation?
A: It's mathematically precise for the given inputs, but real-world factors like tire wear, pressure, and load can affect actual speed.