If you’ve visited any showrooms lately or found yourself perusing a motoring magazine or two, you probably came across horsepower (HP) as something of a hot topic. HP is a unit used to measure the power output of a combustion engine-powered car, from hot hatches to SUVs.
Sometimes referred to as PS – an abbreviation of the German horsepower translation pferdestarke – a car’s HP figure reflects how fast its engine can deliver torque (the rotating force produced by an engine’s crankshaft) to the wheels over a certain period. In short, it’s a measurement of how fast an engine can do its job.
So, why is horsepower important? A car’s horsepower has an enormous influence over its road performance – without it, the car wouldn’t be able to move. On this page, we’ll explore what horsepower is, whether it really is better to have more and how it differs from other power measurements.
What’s the difference between horsepower and brake horsepower?
Horsepower figures are quoted by manufacturers around the world, though brake horsepower (BHP) is another unit commonly used in the UK. BHP differs in that it takes friction losses between a car’s tyres and the road into account when generating the final figure, while HP doesn’t.
The two are nearly identical – one BHP is about 99% of an HP – but on larger scales, the difference becomes more apparent.
Is electric car power measured in HP?
The power output of electric motors is commonly measured in Kilowatts rather than HP. However, in an attempt to make Kilowatt figures more digestible for the common consumer, the two measurements are often compared with each other by manufacturers. For example, if an electric motor produces 200Kw, by multiplying this figure by 1.369, one can calculate it produces 274 HP.
Are horsepower figures accurate?
A vehicle’s horsepower is a measurement of its engine’s power output, but these figures are invariably slightly greater than the amount of power delivered onto the tarmac as there are frictional losses in the transmission between the engine and the road.
The consensus among experts is that a car will lose between 10 and 15 percent of its stated horsepower to friction. One must also assume that the stated power output was achieved with a highly tuned engine in perfect conditions, rather than with a mass-produced example commonly found on the road in variable conditions. To find your car’s true horsepower figure, you’ll need to put it on a rolling
Is more horsepower better?
In the last decade or so, the performance car horsepower arms race has reached unchartered territory. The 812 Superfast, Ferrari’s flagship front-engine GT car, now boasts an HP figure akin to one you might find in a 10-year-old Formula One car, while the power output from the latest crop of Audi and Mercedes super hatches can put a Porsche 911 Carrera S to shame.
On Britain’s bumpy, twisting roads, however, it’s unlikely that you’ll ever need anywhere near that much power. More power is often perceived as better, but as a regular, law-abiding UK motorist, the higher top speeds offered by powerful engines may not be worth the premium.
How much horsepower does your car have?
Check out the Parkers reviews to find out how much horsepower your car has. Here are a few examples:
Lamborghini Aventador horsepower – you’ll find up to 740bhp in this not-very-subtle supercar.
Nissan GTR horsepower: when launched in 2009, the Nissan GTR produced 480hp, but the revised editions from 2017 have increased this to 570hp, while the range-topping Nismo packs 600hp.
Audi R8 horsepower – the high-revving monster of a V10 engine in the R8 gives you 570hp (it was upgraded in 2019, from just 540hp). The R8 V10 Performance gives you even more, with up to 620hp.
BMW i8 horsepower: the i8 develops 357bhp and 570Nm of torque, and can sprint from 0-62mph in 4.4 seconds.
