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Brake to Wheel Formula:
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Brake to wheel horsepower represents the actual power delivered to the wheels after accounting for drivetrain losses. It's typically less than brake horsepower (measured at the engine) due to mechanical losses in the transmission, differential, and other driveline components.
The calculator uses the simple formula:
Where:
Explanation: The calculation accounts for power loss through the drivetrain components before reaching the wheels.
Details: Wheel horsepower is crucial for understanding actual vehicle performance, as it represents the power that actually propels the vehicle. It's used in performance tuning, racing, and vehicle comparisons.
Tips: Enter brake horsepower (measured at the engine) and driveline efficiency (as a decimal between 0 and 1). Typical driveline efficiency values range from 0.75 to 0.95 depending on drivetrain configuration.
Q1: What's the difference between brake HP and wheel HP?
A: Brake HP is measured at the engine crankshaft, while wheel HP is measured at the wheels after drivetrain losses.
Q2: What are typical driveline efficiency values?
A: Rear-wheel drive: 0.80-0.95, Front-wheel drive: 0.75-0.90, All-wheel drive: 0.70-0.85 depending on complexity.
Q3: Why is wheel horsepower lower than brake horsepower?
A: Power is lost through friction in the transmission, driveshaft, differential, and other driveline components.
Q4: How is driveline efficiency determined?
A: Through dynamometer testing comparing engine output to wheel output, or using manufacturer specifications.
Q5: Does this calculation work for electric vehicles?
A: The concept is similar, but EV drivetrains typically have higher efficiency (0.90-0.95) due to fewer moving parts.