1. What is Crank To Wheel Horsepower?

Crank to wheel horsepower conversion calculates the actual power delivered to the wheels after accounting for drivetrain losses. Crank horsepower (engine horsepower) is the power produced by the engine, while wheel horsepower is the power that actually reaches the wheels to propel the vehicle.

2. How Does the Calculator Work?

The calculator uses the wheel horsepower formula:

Where:

• \( Wheel\ HP \) — Power at wheels after losses (hp)
• \( Crank\ HP \) — Engine horsepower at the crankshaft (hp)
• \( Drivetrain\ Efficiency \) — Efficiency factor accounting for power losses (decimal)

Explanation: The formula accounts for power losses through the transmission, driveshaft, differential, and other drivetrain components. A typical drivetrain efficiency of 0.85 (85%) is used for most rear-wheel drive vehicles.

3. Importance of Wheel Horsepower Calculation

Details: Wheel horsepower represents the actual power available for acceleration and performance. Understanding the difference between crank and wheel horsepower is crucial for vehicle performance tuning, dyno testing, and realistic performance expectations.

4. Using the Calculator

Tips: Enter crank horsepower in horsepower units and drivetrain efficiency as a decimal (e.g., 0.85 for 85% efficiency). Typical efficiency values range from 0.80-0.90 depending on drivetrain type and condition.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical drivetrain efficiency for different vehicles?
A: Rear-wheel drive: 0.85-0.90, Front-wheel drive: 0.80-0.85, All-wheel drive: 0.75-0.85 depending on complexity.

Q2: Why is there power loss between crank and wheels?
A: Power is lost through friction in transmission gears, driveshaft bearings, differential, and tire deformation.

Q3: How accurate is this calculation?
A: It provides a good estimate, but actual dyno testing is needed for precise measurements as efficiency can vary with vehicle condition and operating conditions.

Q4: Does drivetrain efficiency change over time?
A: Yes, worn components, old transmission fluid, and poor maintenance can reduce efficiency over time.

Q5: Can I use this for electric vehicles?
A: Electric vehicles typically have higher drivetrain efficiency (0.90-0.95) due to simpler transmission systems and fewer moving parts.