Check a car's BHP

How is brake horsepower measured?

Brake horsepower is measured on a dynamometer, which applies a load to the engine and records the torque and rotational speed to calculate power. The "brake" refers to the resistance historically applied to the engine's flywheel.

The concept of horsepower itself dates back to engineer James Watt, who compared steam engines to the pulling power of horses. Today the dynamometer gives a standardised, repeatable measure of an engine's output.

What is the difference between BHP, PS and kW?

BHP, PS and kW all measure the same thing — power — in different units. PS is the European (German) equivalent of horsepower, and kW is the metric unit, where 1 kW is roughly 1.34 horsepower.

You will often see all three quoted for the same car, especially on newer and electric vehicles where power is increasingly given in kW. BHP is usually a slightly lower figure than raw horsepower because it accounts for the engine's internal losses.

How do you check a car's BHP by registration?

You check a car's BHP by entering the registration into a vehicle check, which looks up the recorded power output and specification for that exact vehicle.

This matters because different trims and engine variants of the same model can have very different power figures. Checking the specific car avoids relying on the badge or the seller's word.

1. Enter the registration into the BHP check above.
2. See the power output in BHP, with kW and PS where available.
3. Confirm it matches the trim and engine variant the seller is describing.

What is a good BHP for a car?

There is no single answer, but around 130 BHP is a comfortable middle ground for everyday driving. Family cars typically sit at 100–150 BHP, 200–300 BHP is sporty, and over 400 BHP is high-performance territory.

More power is not automatically better. A higher figure usually means higher running costs and insurance, so the right BHP depends on how and where you drive rather than chasing the biggest number.

How does BHP affect performance?

More BHP generally means quicker acceleration, but it is not the whole story — weight, transmission and grip all matter. As a rough guide, a 0–60 mph time of 6–7 seconds is considered quick.

A light car with modest power can feel livelier than a heavy car with a big figure, which is why power-to-weight matters as much as BHP alone. Use the figure as a guide to character, not an absolute measure of speed.

Does BHP affect insurance?

Indirectly, yes. More powerful cars often sit in higher insurance groups, but BHP is only one factor — insurers also weigh the car's value, the Thatcham insurance group, your age, location and claims history.

So a higher-BHP car will often cost more to insure, but not always, and not in proportion to the power figure alone. It is worth getting a quote before you buy a more powerful car.

Why check BHP before buying?

Checking the BHP confirms the exact specification, helps you judge running and insurance costs, and verifies the car is the variant the seller claims it is.

A spec check is most useful read alongside the history. A more powerful car is more likely to have been driven hard, so pair the power figures with a mileage check and a write-off check before you commit.