Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.

Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.

Automotive Calculators

Vehicle Comparison Calculator

2026-09-27 6 min

Compare two vehicles on power-to-weight and dollars per horsepower.

Power-to-Weight A: 57.14 hp/1000lb
Power-to-Weight B: 69.44 hp/1000lb
Cost per HP A: 125.00 $/hp
Cost per HP B: 120.00 $/hp

Calculator

Price — Vehicle A($)

Horsepower — A(hp)

Weight — A(lb)

Price — Vehicle B($)

Horsepower — B(hp)

Weight — B(lb)

Results update live as you type

Live statistics

Power-to-Weight A

57.14 hp/1000lb

Power-to-Weight B

69.44 hp/1000lb

Cost per HP A

125.00 $/hp

Cost per HP B

120.00 $/hp

Results

Optimal

Power-to-Weight A

57.14hp/1000lb

Power-to-Weight B

69.44hp/1000lb

Cost per HP A

125.00$/hp

Cost per HP B

120.00$/hp

Planning estimate from standard automotive formulas. Validate with dyno, timeslip or datalog data when precision matters.

Visualizations

Results overview

57.1Power-to-Weight A

69.4Power-to-Weight B

125Cost per HP A

120Cost per HP B

Power-to-Weight B vs. Price — Vehicle A

Power-to-Weight B

69.4hp/1000lb

0120

Formula

Normalizes power by mass and price so mismatched vehicles compare fairly.

P:W = hp / weight x 1000; $/hp = price / hp

Alternative Form

Higher hp/1000lb predicts quicker acceleration at similar grip

Variables

Symbol	Name	Unit	Description
P:W	Power to weight	hp/1000lb	Horsepower per 1,000 lb
$/hp	Dollars per hp	$/hp	Purchase cost per horsepower

Explanation

Weight dilutes power and price dilutes value — these two ratios capture both effects in one view.

Step-by-Step Calculation

Follow each step to understand how the result is calculated from your inputs.

Step 1

Record the inputs.

Price — Vehicle A:25000 $

Horsepower — A:200 hp

Weight — A:3500 lb

Price — Vehicle B:30000 $

Horsepower — B:250 hp

Weight — B:3600 lb

Result: 6 inputs ready

Step 2

Apply the formula.

P:W = hp / weight x 1000; $/hp = price / hp

Result: Primary result = 69.44 hp/1000lb

Step 3

Read every derived output.

Power-to-Weight A:57.14 hp/1000lb

Power-to-Weight B:69.44 hp/1000lb

Cost per HP A:125.00 $/hp

Cost per HP B:120.00 $/hp

Result: Power-to-Weight B = 69.44 hp/1000lb

Final Answer

57.14

Worked Examples

See how the calculator works with different scenarios.

Scenario

Base vs upgrade trim comparison.

Inputs

A:200 hp, 3,500 lb

B:250 hp, 3,600 lb

Calculation

P:W A = 57.1, B = 69.4; $/hp A = $125, B = $120

Result

B is quicker and cheaper per hp.

Interpretation

The upgrade trim is the performance value here.

Understanding Your Result

Your Result: Power-to-Weight A: 57.14 hp/1000lb

Typical range: Family cars 40-70, sports cars 70-120, supercars 150+ hp/1000lb.

What This Means

Which vehicle moves each pound cheapest and hardest.

Why It Matters

Raw hp lies — weight and price decide the real performance deal.

Professional Interpretation

Treat the primary result as a planning estimate, then validate on a dyno, at the track, or with logged sensor data. If measured numbers disagree by more than ~10%, re-check inputs (units are the usual culprit) before changing parts.

Recommendations

•Double-check units on every input before trusting the result
•Compare against the worked example below to sanity-check magnitude
•Validate with measured data (dyno, timeslip, datalog) when it matters

Learn — fuel economy, deeply

Vehicle comparison turns brochure hp into weight- and price-adjusted ratios.

1 · Where the gallon goes (energy path)

Engine heat

60–70% lost

Coolant + exhaust carry most energy away. Hybrids recover some via Atkinson cycle + regen.

Driveline

5–15% lost

Transmission, differential, accessories. CVTs and 8–10 speed autos lose less.

Aero drag

∝ v²

Doubles from 55→78 mph. Roof boxes hurt more than trunks.

Rolling + brakes

10–20%

Tires, weight, stops. Regen braking (hybrid/EV) reclaims city braking energy.

4 · Measure like a pro (the 3-tank protocol)

Fill to first click at the same pump, record the odometer (Tank 0).
Drive normally for 2–3 tanks; always refill to first click at the same pump.
MPG = total miles ÷ total gallons across all tanks — averaging kills pump-click noise.
Cross-check with the trip computer; a persistent >10% gap means the computer needs calibration — or the car needs service.
Log with an OBD-II dongle for per-trip MPG if you want to isolate commute vs. highway behavior.

Practical Tips

•Use curb weight, not dry weight
•Compare same fuel/condition hp ratings
•Lower $/hp is better value

Common Mistakes

Mixing units (inches with mm, psi with kPa)

Convert every input to the unit shown on its field before calculating.

Trusting a single output blindly

Cross-check with the worked example and, when it matters, a dyno or datalog.

Assumptions

This calculator makes the following assumptions to provide estimates:

Steady-state model: Formulas assume stabilized conditions; transients, heat soak and traction limits are excluded.

Standard factors: Empirical constants (BSFC, VE, drivetrain loss) use typical values — your combination may differ.

Limitations

Be aware of these limitations when using this calculator:

Estimate, not measurement: Predictions carry real-world scatter of roughly ±5–15% depending on the model.

No transient effects: Shift time, wheelspin, spool lag and heat soak are not modeled here.

Frequently Asked Questions

Answers to common questions about this calculator.

What is a good power-to-weight ratio?

Around 50-70 hp/1000lb for family cars, 90+ for sporty cars. Higher means livelier acceleration.

What does dollars per horsepower tell me?

How much you pay for each horsepower — lower is better performance value, ignoring handling and economy.

Related Calculators

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Related Guides

Deepen your understanding with these educational resources.

Automotive Guides

Build planning, measurement protocol and validation how-tos

Glossary

Technical terms used in mortgage calculations explained in plain language.

MPG: Miles per gallon. Distance travelled per gallon of fuel; higher is better. US gallon = 3.785 L.
L/100 km: Litres consumed per 100 kilometres; lower is better. Standard metric efficiency unit.
MPGe: Miles per gallon-equivalent. EV metric: miles travelled on 33.7 kWh (energy of 1 gal of gasoline).
CAFE: Corporate Average Fuel Economy — US fleet-average efficiency standard enforced by NHTSA.
Rolling resistance: Energy lost deforming tires as they roll. Low-pressure or wide tires raise it.
Aerodynamic drag: Air resistance growing with the square of speed — why highway MPG falls fast above 60 mph.
Hypermiling: Driving techniques (coasting, steady speed, anticipation) that maximise real-world MPG.
OBD-II: On-board diagnostics port. Scanners and dongles read live MPG, fuel trim and fault codes.

Authoritative References

Trusted sources and standards referenced by this calculator.

EPA — FuelEconomy.gov DOE — Fuel-Efficient Driving Tips NHTSA — Driving Safety & Efficiency SAE International — Fuel Economy Standards Consumer Reports — MPG Truth IRS — Standard Mileage Rates

Applicable Standards

EPA Fuel Economy Testing (40 CFR Part 600)CAFE — Corporate Average Fuel Economy Standards (NHTSA)WLTP — Worldwide Harmonised Light Vehicle Test ProcedureSAE J1321 / J1711 — Fuel consumption test proceduresISO 2575 — Road vehicles symbols & efficiency markings

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Last Updated:

2026-09-27

Version:

2.0.0

References:

License:

Free to use for educational and professional purposes.