1. What is 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 the engine horsepower due to friction and mechanical losses in the transmission, differential, and other drivetrain components.

2. How Does the Calculator Work?

The calculator uses the Wheel Horsepower formula:

Where:

• \( WHP \) — Wheel Horsepower (power at the wheels)
• \( HP \) — Engine Horsepower (power at the crankshaft)
• \( \text{Drivetrain Loss} \) — Power lost in the drivetrain (typically 0.10-0.20 for RWD, 0.15-0.25 for AWD)

Explanation: The equation accounts for power lost between the engine and wheels due to friction and mechanical inefficiencies in the drivetrain components.

3. Importance of WHP Calculation

Details: WHP is crucial for understanding a vehicle's actual performance capabilities, tuning modifications, and comparing different vehicles on equal terms.

4. Using the Calculator

Tips: Enter engine horsepower in HP and drivetrain loss as a decimal (e.g., 0.15 for 15%). Typical values are 0.15 for RWD, 0.20 for FWD, and 0.25 for AWD vehicles.

5. Frequently Asked Questions (FAQ)

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

Q2: What's a typical drivetrain loss percentage?
A: Rear-wheel drive: ~15%, Front-wheel drive: ~10-15%, All-wheel drive: ~20-25%. This varies by vehicle and drivetrain condition.

Q3: How is WHP measured?
A: WHP is measured on a dynamometer (dyno) by applying resistance to the wheels and measuring the torque and RPM.

Q4: Does WHP change with modifications?
A: Yes, modifications like lighter wheels, improved drivetrain components, or reduced friction can increase WHP without changing engine HP.

Q5: Is WHP the same as BHP?
A: No, BHP (brake horsepower) is measured at the crankshaft (before drivetrain losses), while WHP is measured at the wheels (after losses).