Help solve a PS / BHP discussion

[Urban Sports]

Good evening,

I had a discussion last night with my Dad and Brother, about PS and BHP, I have always thought, mainly from reading about BHP figures that the equivalent PS figure to BHP is usually higher, as an example the MK 5 Golf GTI is 197 BHP / 200 PS or the Audi S3 is 261 BHP / 265 PS.....and so on.

I have always taken it for granted that you multiply the PS figure by 0.985(ish) to get BHP or divided the BHP figure by 0.985(ish) to get PS.

My Brother and Dad seem to think it's the other way round and the PS figure is lower than the BHP. I've taken a look on the interweb and it tends to sway in my favour but some information sways in theirs

Any ideas?

[Petrolhead_Rich]

"One PS is about 98.6% of a single brake horsepower"

Source

[blank]

1 horsepower equals 1.013869665 PS.

[hardcorehobbit]

Quoted PS are always higher than the BHP.

Case in point, the Lamborghini Murcielago LP 640 doesn't have 640 BHP, it has less.

[Zwolf]

You are correct, they are wrong.

Now ask them about kiloWatts.

[OdramaSwimLaden]

Blah blah blah....

PS.....you're right!

[Urban Sports]

Petrolhead_Rich said:

"One PS is about 98.6% of a single brake horsepower"

Source

See, that shows it to be the exact opposite calculation!

Which is correct?

[EV11NED]

blank said:

1 horsepower equals 1.013869665 PS.

This is correct. PS is a German standard measure (pferdesterke), and is in the ratio to bhp as quoted above. That's why the Golf GTi is 200PS and 197BHP.

[66comanche]

Urban Sports said:

Petrolhead_Rich said:

"One PS is about 98.6% of a single brake horsepower"

Source

See, that shows it to be the exact opposite calculation!

Which is correct?

It doesn't, unless I'm also getting confused!

[GravelBen]

See also the old Japanese 'Honourable Manufacturers Agreement' power limit of 280PS / 276BHP. (Or 206 kW )

[Urban Sports]

66comanche said:

Urban Sports said:

Petrolhead_Rich said:

"One PS is about 98.6% of a single brake horsepower"

Source

See, that shows it to be the exact opposite calculation!

Which is correct?

It doesn't, unless I'm also getting confused!

It shows if you type 197 bhp (Golf GTI) that it's 194 ps not the 200 ps that VW say.

[kambites]

PS is the smaller unit, so will be a bigger number for a given car.

[kambites]

Urban Sports said:

It shows if you type 197 bhp (Golf GTI) that it's 194 ps not the 200 ps that VW say.

No it doesn't. If one PS is 0.9xxxx BHP, then a car will have more PS than BHP, because it's the smaller unit.

[Urban Sports]

kambites said:

PS is the smaller unit, so will be a bigger number for a given car.

Yes as in it takes more PS to do the work of a BHP therefore the equivalent figure will always be higher.

[Urban Sports]

kambites said:

Urban Sports said:

It shows if you type 197 bhp (Golf GTI) that it's 194 ps not the 200 ps that VW say.

No it doesn't. If one PS is 0.9xxxx BHP, then a car will have more PS than BHP, because it's the smaller unit.

On the power converter on that site it does, and it won't convert 1 unit into a decimal anyway, it obviously rounds it.

[GroundEffect]

Metric HP (PS) is a smaller value than Imperial HP

[Urban Sports]

GroundEffect said:

Metric HP (PS) is a smaller value than Imperial HP

So would need a higher value to be equivalent.