1. What is Wheel Horsepower?

Wheel horsepower is the actual power that reaches the wheels after accounting for drivetrain losses. It's typically 10-20% less than engine horsepower due to transmission, differential, and other mechanical losses.

2. How Does the Calculator Work?

The calculator uses the wheel horsepower formula:

Where:

• Engine HP — The horsepower measured at the engine crankshaft
• Transmission Efficiency — The efficiency of the drivetrain (typically 0.80-0.90 for rear-wheel drive, 0.85-0.95 for front-wheel drive)

Explanation: The equation accounts for power loss through the transmission and drivetrain components.

3. Importance of Wheel HP Calculation

Details: Wheel horsepower is what actually propels the vehicle and is more relevant for performance measurements than engine horsepower. It's used in dyno testing and performance tuning.

4. Using the Calculator

Tips: Enter engine horsepower in HP and transmission efficiency as a decimal between 0 and 1 (e.g., 0.85 for 85% efficiency). All values must be valid (HP > 0, efficiency between 0-1).

5. Frequently Asked Questions (FAQ)

Q1: What's typical transmission efficiency?
A: Rear-wheel drive: 80-90%, Front-wheel drive: 85-95%, All-wheel drive: 75-85%.

Q2: Why is wheel HP less than engine HP?
A: Power is lost through friction in the transmission, differential, and other drivetrain components.

Q3: How is wheel HP measured?
A: Typically measured on a dynamometer (dyno) which measures torque and calculates horsepower.

Q4: Does transmission type affect efficiency?
A: Yes, manual transmissions are generally more efficient than automatics by 5-10%.

Q5: Can wheel HP be higher than engine HP?
A: Normally no, unless there's measurement error or the engine HP rating is conservative.