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Speed Formula:
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The Speed RPM Gear Ratio formula calculates vehicle speed based on engine RPM, tire circumference, and gear ratio. This is particularly useful in automotive engineering and performance tuning to understand vehicle performance characteristics.
The calculator uses the formula:
Where:
Explanation: The formula calculates how fast a vehicle is moving based on engine speed, tire size, and gear reduction. The constant 336 converts units to miles per hour.
Details: Accurate speed calculation is crucial for vehicle performance analysis, gear selection, fuel efficiency optimization, and ensuring compliance with speed regulations.
Tips: Enter RPM in revolutions per minute, tire circumference in inches, and gear ratio as a decimal value. All values must be positive numbers.
Q1: How do I measure tire circumference?
A: Measure the distance around the outside of the tire, or calculate it using the tire diameter (Circumference = π × Diameter).
Q2: What is a typical gear ratio range?
A: Gear ratios typically range from 2.5:1 to 4.5:1 for most passenger vehicles, with lower ratios providing better acceleration and higher ratios providing better fuel economy.
Q3: Why is the constant 336 used in the formula?
A: The constant 336 converts inches per minute to miles per hour (12 inches/foot × 5280 feet/mile ÷ 60 minutes/hour = 1056, then adjusted for the formula).
Q4: Does this formula account for tire slip?
A: No, this formula calculates theoretical speed. Actual speed may vary due to tire slip, transmission efficiency, and other factors.
Q5: Can I use this for different vehicle types?
A: Yes, the formula works for any wheeled vehicle, but accuracy may vary based on drivetrain efficiency and other vehicle-specific factors.