Crank Torque To Wheel Torque Calculator

Wheel Torque Equation:

\[ T_{wheel} = T_{crank} \times gear\_ratio \times final\_drive \times eff \]

Crank Torque (T_crank):

Gear Ratio:

dimensionless

Final Drive:

dimensionless

Efficiency (eff):

dimensionless

Wheel Torque (T_wheel):

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1. What is the Wheel Torque Equation?

The wheel torque equation calculates the torque delivered to the wheels from the engine crank torque, taking into account gear ratio, final drive ratio, and drivetrain efficiency. It provides a measure of the actual torque available at the wheels for vehicle propulsion.

2. How Does the Calculator Work?

The calculator uses the wheel torque equation:

\[ T_{wheel} = T_{crank} \times gear\_ratio \times final\_drive \times eff \]

Where:

\( T_{crank} \) — Engine crank torque (Nm)
\( gear\_ratio \) — Current gear ratio (dimensionless)
\( final\_drive \) — Final drive ratio (dimensionless)
\( eff \) — Drivetrain efficiency (dimensionless, typically 0.85-0.95)

Explanation: The equation multiplies the engine torque by the gear reduction ratios and accounts for power losses through the drivetrain to determine the actual torque delivered to the wheels.

3. Importance of Wheel Torque Calculation

Details: Wheel torque calculation is essential for understanding vehicle performance characteristics, including acceleration, towing capacity, and hill-climbing ability. It helps in gear selection and transmission design.

4. Using the Calculator

Tips: Enter crank torque in Nm, gear ratio, final drive ratio, and efficiency factor. All values must be positive numbers (efficiency typically between 0.8-1.0).

5. Frequently Asked Questions (FAQ)

Q1: Why is efficiency less than 1?
A: Efficiency accounts for power losses in the transmission, driveshaft, differential, and other drivetrain components due to friction and heat.

Q2: How does gear ratio affect wheel torque?
A: Lower gear ratios (higher numerical values) multiply torque more significantly, providing greater wheel torque at the expense of wheel speed.

Q3: What is a typical efficiency value?
A: Most modern drivetrains have efficiencies between 85-95%, with manual transmissions typically being more efficient than automatics.

Q4: Does this calculation work for all vehicle types?
A: The equation applies to all wheeled vehicles with mechanical drivetrains, including cars, trucks, motorcycles, and bicycles.

Q5: How does wheel torque relate to vehicle acceleration?
A: Higher wheel torque results in greater acceleration force, though actual acceleration also depends on vehicle weight, traction, and aerodynamic drag.