1. What Is The Crank Torque To Wheel Torque Calculation?

The crank torque to wheel torque calculation determines the actual torque delivered to the wheels of a vehicle based on engine torque, transmission ratio, and axle ratio. This is essential for understanding a vehicle's acceleration performance and pulling power.

2. How Does The Calculator Work?

The calculator uses the wheel torque formula:

Where:

• Crank Torque — Engine torque output (N·m)
• Transmission Ratio — Current gear ratio (unitless)
• Axle Ratio — Final drive/differential ratio (unitless)

Explanation: The transmission multiplies engine torque based on the selected gear, and the differential further multiplies this torque before it reaches the wheels.

3. Importance Of Wheel Torque Calculation

Details: Wheel torque directly affects a vehicle's acceleration, towing capacity, and hill-climbing ability. Understanding wheel torque helps in vehicle performance analysis, gear selection optimization, and comparing different drivetrain configurations.

4. Using The Calculator

Tips: Enter crank torque in N·m, transmission ratio (typically between 2.5-4.0 for lower gears, 0.6-1.0 for higher gears), and axle ratio (typically between 2.5-4.5 for most vehicles). All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is wheel torque different from engine torque?
A: Gear ratios in the transmission and differential multiply the engine torque, resulting in higher torque at the wheels, particularly in lower gears.

Q2: How does gear selection affect wheel torque?
A: Lower gears have higher multiplication ratios, resulting in more wheel torque but less wheel speed. Higher gears provide less multiplication but higher speed.

Q3: What is a typical axle ratio range?
A: Most passenger vehicles have axle ratios between 2.5:1 and 4.5:1. Performance and towing vehicles often have higher ratios for increased torque.

Q4: Does wheel size affect wheel torque?
A: While the calculation gives torque at the wheel hub, larger diameter wheels effectively reduce the force applied to the road surface due to the increased lever arm.

Q5: How accurate is this calculation for real-world applications?
A: This provides a theoretical maximum that doesn't account for drivetrain losses (typically 15-20%), tire grip, or other real-world factors, but is excellent for comparison purposes.