1. What is Power-to-Weight Ratio?

Definition: This calculator determines the power-to-weight ratio by dividing the engine's horsepower by the vehicle's weight.

Purpose: It helps automotive enthusiasts and engineers compare vehicle performance potential, as a higher ratio typically means better acceleration.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( \text{HP/W} \) — Power-to-weight ratio (horsepower per pound)
• \( \text{HP} \) — Engine horsepower
• \( \text{W} \) — Vehicle weight (pounds)

Explanation: The ratio shows how much power is available to move each pound of vehicle weight.

3. Importance of Power-to-Weight Ratio

Details: This metric is crucial for comparing vehicle performance, as it directly relates to acceleration capability and overall dynamic performance.

4. Using the Calculator

Tips: Enter the engine's horsepower and the vehicle's weight in pounds. Both values must be > 0.

5. Frequently Asked Questions (FAQ)

Q1: What's a good power-to-weight ratio?
A: For street cars, 0.05-0.08 HP/lb is good, 0.08-0.10 is excellent, and >0.10 is exceptional. Race cars often exceed 0.15 HP/lb.

Q2: Should I use curb weight or gross weight?
A: For performance comparisons, use curb weight (empty vehicle weight). For practical applications, you might use gross weight (including passengers/cargo).

Q3: How can I improve my power-to-weight ratio?
A: Either increase horsepower (engine modifications) or decrease weight (lightweight components, removing unnecessary items).

Q4: Does this account for drivetrain losses?
A: No, this uses engine horsepower. For wheel horsepower, multiply by drivetrain efficiency (typically 0.85 for RWD, 0.80 for FWD, 0.75 for AWD).

Q5: How does this compare to torque-to-weight ratio?
A: While HP/W indicates top speed potential, torque-to-weight better predicts low-end acceleration. Both are important performance metrics.