BHP check

A BHP check tells you how much power a car was built with. It's worth knowing before you buy. Power affects the price, the insurance group, how the car drives and, on some models, which engine you're actually getting. Enter the registration and we'll show you the car's free DVLA details straight away, with the power output on its factory spec sheet.

How to check a car's BHP by registration

1. Enter the reg in the box above. The free check confirms the make, model, engine size and fuel type from the DVLA, along with the MOT history and mileage.
2. Get the factory spec sheet. It's part of the Service history check (£8.99) and the Ultimate report (£10.49). It's decoded from the car's VIN, and shows the exact engine and power output, plus the gearbox, trim and factory options.
3. Compare it with the advert. If the seller is quoting a different figure, ask why.

Why engine size isn't enough

The same size engine often comes in several power outputs. A 2.0-litre diesel might be sold at 150, 190 and 240 PS in the same model range, and those versions can be thousands of pounds apart in value. The badge on the boot doesn't always help either, because badges are easy to change and some manufacturers dropped engine badges altogether.

That's why a BHP check matters on cars where the model name alone doesn't tell you the whole story, including hot hatches, performance saloons, SUVs and most modern diesels. If you're paying for the more powerful version, make sure that's what you're getting.

BHP, PS and kW explained

Car power is quoted in three units, and adverts often mix them up:

• bhp (brake horsepower) is the traditional British figure.
• PS (metric horsepower, from the German Pferdestärke) is what most European manufacturers quote. It's also written as "hp" or "cv" in some brochures.
• kW (kilowatts) is the official unit, and the one printed on the V5C logbook.

Handy conversions:

• 1 PS = 0.986 bhp, so 150 PS is about 148 bhp.
• 1 kW = 1.341 bhp, so 100 kW is about 134 bhp.
• 1 kW = 1.36 PS, so 110 kW is about 150 PS.

The difference between PS and bhp is small, about 1.4%. It isn't a reason to worry if an advert says 150 bhp and the spec says 150 PS.

Does the V5C show BHP?

Not directly. Most V5C logbooks show the maximum net power in kilowatts in section P.2, next to the engine size in cc (P.1) and the fuel type (P.3). Multiply the kW figure by 1.341 to get bhp. On some older cars P.2 is blank, which is where the factory spec sheet helps. Our car spec check page explains the other V5C sections.

Has the car been remapped?

A remap changes the engine's software to make more power. Remaps aren't recorded by the DVLA or the manufacturer, so no reg check can show one. What a BHP check gives you is the figure the car should have, which is your starting point.

Signs that a car may have been modified:

• The seller talks about "stage 1", "stage 2", a tune or a custom map.
• There's a non-standard exhaust, intake or intercooler, or a box plugged into the engine wiring.
• It feels noticeably quicker than the same model should, or smokes heavily under hard acceleration.
• The service history, if you can see it, shows gaps or work done at tuning specialists.

A rolling road test is the only way to measure a car's real power. If you think a car has been remapped, ask for proof of what was done and who did it, and bear in mind that a remap can affect the warranty and put extra strain on the clutch, turbo and gearbox.

BHP and insurance

Every car is given an insurance group from 1 to 50, and power and performance are among the factors that set it. More power usually means a higher group and a higher premium. That matters most for new and young drivers.

If a car has more power than standard, you must tell your insurer. An undeclared remap or modification can lead to a claim being refused or a policy being cancelled, even if the previous owner made the change and didn't tell you.

BHP and car tax

Power doesn't affect car tax directly. For cars first registered from April 2017, the first year's tax is based on CO2 emissions, and after that most cars pay the standard rate. Cars registered between March 2001 and April 2017 are taxed on CO2 bands, and older cars on engine size. See what a car costs to tax with our free car tax check.

Check the history as well as the power

Knowing the power tells you what the car should be. It doesn't tell you whether it has outstanding finance, has been written off or is recorded as stolen, and performance cars are more likely than most to have a past. Our Full check (£8.99) covers all of that, and the Ultimate report (£10.49) adds service history and the factory spec sheet in one report.