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Wheel Horsepower Formula:
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Wheel Horsepower (WHP) is the actual power measured at the wheels of a vehicle. It represents the usable power that propels the vehicle forward, accounting for power losses through the drivetrain.
The calculator uses the WHP formula:
Where:
Explanation: The formula calculates the actual power delivered to the wheels by accounting for power losses in the transmission, differential, and other drivetrain components.
Details: WHP provides a more accurate measure of a vehicle's actual performance capabilities than engine horsepower alone. It's crucial for performance tuning, racing applications, and understanding real-world vehicle dynamics.
Tips: Enter engine horsepower (typically provided by manufacturers) and drivetrain efficiency (typically 0.85-0.90 for rear-wheel drive, 0.80-0.85 for front-wheel drive, and 0.75-0.85 for all-wheel drive vehicles).
Q1: Why is WHP lower than engine horsepower?
A: WHP is lower due to power losses through the transmission, driveshaft, differential, and other drivetrain components before reaching the wheels.
Q2: What is a typical drivetrain efficiency value?
A: Typical values range from 0.75 to 0.90 depending on the drivetrain type, with manual transmissions generally being more efficient than automatics.
Q3: How is WHP measured in real-world testing?
A: WHP is typically measured using a dynamometer (dyno) which measures the torque and rotational speed at the wheels.
Q4: Can WHP be higher than engine horsepower?
A: No, WHP is always equal to or less than engine horsepower due to inherent drivetrain losses.
Q5: Why is WHP important for performance tuning?
A: WHP represents the actual power that accelerates the vehicle, making it the most relevant metric for performance improvements and comparisons.