Horsepower vs torque: what each figure tells you
Torque describes a twisting force; power describes how quickly work can be done. Neither peak number tells the whole story of how a car accelerates.
Torque and power are connected
An engine dynamometer measures torque and rotational speed; power is derived from them. In U.S. customary units, horsepower equals torque in pound-feet multiplied by rpm and divided by 5,252. Metric units use a different conversion.
This is why a large low-speed torque figure can describe effortless initial response, while an engine that maintains torque at higher rpm can produce greater peak power. The full curve is more informative than either maximum.
How to read the numbers
| Specification | What it describes | What it misses |
|---|---|---|
| Peak torque | Highest measured twisting force | Where and how broadly it is available |
| Peak horsepower | Highest rate of doing work | Vehicle weight and gearing |
| 0–100 km/h time | Whole-vehicle acceleration test | Passing response and repeatability |
| Power-to-weight | Output relative to mass | Traction, gearing and aerodynamics |
A better way to compare cars
Compare outputs only when the units and test conventions match. Then consider curb weight, transmission ratios, drive wheels and the engine speed at which peak figures occur. Electric motors and combustion engines can have very different torque curves, so comparing peak torque alone is especially misleading.
- Convert kW, PS and hp carefully; they are not identical units.
- Look for a torque range, not only a single peak rpm.
- Use instrumented acceleration tests only when conditions and vehicle versions are comparable.
Explore the catalog
Apply these concepts to real model-generation and body-style pages in the Autotras catalog.
Sources and editorial note
This guide explains general engineering distinctions. Exact behavior and terminology can differ by manufacturer, market and model year; check the owner’s manual and specifications for the exact vehicle.
- NIST — SI units and conversion resources — authoritative unit definitions and conversion guidance
- SAE International — J1349 engine power test code — standardized engine power and torque measurement
See how we handle vehicle data in our data methodology, or report a correction.