1. What is Crank to Wheel Horsepower?

Wheel Horsepower (WHP) is the actual power that reaches the wheels after accounting for drivetrain losses. It's typically 10-20% less than crank horsepower (CHP) due to friction and other losses in the transmission, differential, and other drivetrain components.

2. How Does the Calculator Work?

The calculator uses the simple formula:

Where:

• \( WHP \) — Wheel Horsepower (output at the wheels)
• \( CHP \) — Crank Horsepower (engine output)
• \( Efficiency \) — Drivetrain efficiency (typically 0.80-0.90)

Explanation: The equation accounts for power loss between the engine and wheels, with different drivetrain types having different typical efficiency values.

3. Importance of WHP Calculation

Details: WHP is crucial for understanding actual vehicle performance, as it represents the power that's truly available to move the vehicle. It's more relevant than CHP for performance tuning and comparisons.

4. Using the Calculator

Tips: Enter crank horsepower in hp and drivetrain efficiency as a decimal (e.g., 0.85 for 85%). Typical efficiency values are 0.85 for RWD, 0.88 for FWD, and 0.82 for AWD vehicles.

5. Frequently Asked Questions (FAQ)

Q1: Why is WHP lower than CHP?
A: Power is lost through friction in the transmission, driveshaft, differential, and other drivetrain components before reaching the wheels.

Q2: What are typical drivetrain efficiency values?
A: Front-wheel drive: ~88%, Rear-wheel drive: ~85%, All-wheel drive: ~80-82%. Manual transmissions typically lose less power than automatics.

Q3: How is WHP measured?
A: WHP is measured on a dynamometer (dyno) by applying resistance to the wheels and measuring the force required to turn them.

Q4: Can WHP be higher than CHP?
A: No, WHP is always less than or equal to CHP due to unavoidable drivetrain losses.

Q5: Why is WHP more important than CHP?
A: WHP represents the actual power available to move the vehicle, making it more relevant for performance evaluation and tuning.