Estimating 0–60 mph
The 0–60 tool uses equation 2–3 from the final technical support document for NHTSA’s model-year 2024–2026 CAFE rule. NHTSA used the equation to estimate acceleration from the relationship between weight and power in its regulatory analysis. NHTSA final technical support document
Estimated time (s) = 1.8514 + 0.5991 × curb weight (kg) ÷ rated power (kW)
The number is an approximation for planning. Launch, traction, gearing, tires, surface, and timing conventions can affect measured times. The optional drivetrain selection gives context for interpreting the estimate. It does not adjust the equation.
Calibrating to your measured time
If you enter a measured baseline, the site divides it by the baseline model estimate. The upgrade tool multiplies each modeled upgrade time by that scale. The target tool divides the requested time by the same scale before solving the equation. Use comparable timing and launch conditions, including any rollout.
Each upgrade applies its power and weight changes to the original vehicle independently. Cost per 0.10 s divides the cost by the number of tenths saved. The calculation uses the full time difference before rounding.
Solving for power or weight
Let the gap be the target time divided by the calibration scale, minus 1.8514 s. The scale is 1 when you use the model baseline.
Required power (kW) = 0.5991 × current curb weight (kg) ÷ gap
Maximum curb weight (kg) = current power (kW) × gap ÷ 0.5991
The inverse requires a positive gap. A target at or below the effective minimum is outside this model’s range. Each result keeps the other variable fixed.
Power-to-weight and unit conversions
The US ratios are weight in pounds divided by mechanical horsepower, and 2,000 times mechanical horsepower divided by pounds. The metric ratio is 1,000 times rated kilowatts divided by kilograms. One pound equals 0.45359237 kg, one mechanical horsepower is approximately 0.745699872 kW, and one mile per hour equals 1.609344 km/h. NIST Guide to the SI, Appendix B.8
Enter the manufacturer’s engine or system rating. Metric horsepower (PS) and wheel horsepower use different bases. Convert a PS rating to kW or use the manufacturer’s kW specification directly.
Quarter-mile elapsed time and trap speed
These empirical equations use total race weight and peak rated power. Track conditions, launch, gearing, and aerodynamics can change the measured result. Quarter-mile equation reference
ET (s) = 5.825 × ∛(race weight in lb ÷ rated hp)
Trap speed (mph) = 234 × ∛(rated hp ÷ race weight in lb)
Use curb weight for 0–60 and power-to-weight calculations. Use race weight for the quarter mile, including the driver, actual fuel load, and any equipment or cargo carried during the run.
Read the performance guides for worked examples on timing, power-to-weight changes, and race weight.