HP versus BHP (same thing or diffferent?)

[noelsaw]

This is an extension of the debate on whether or not there is a difference between horsepower (hp) and brake horsepower (bhp)from the G35 Debut forum (http://forums.freshalloy.com/forum/Forum19/HTML/000087-5.html)

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by noelsaw:
Infiniti,
HP and BHP are the same thing.

<HR></BLOCKQUOTE>

<BLOCKQUOTE><font size="1" face="Verdana, Arial[/img]quote:</font><HR>Originally posted by Infiniti:
No, hp is still advertised. As seen with any car! http://forums.freshalloy.com/forum/images/icons/smile.gif The 340hp Q, thats not bhp. Dyno the Q and youll get 300-320bhp. The Max has 222hp but dyno it and you get 180-190bhp. 300hp lexus GS430, dyno it and youll get like 270-280bhp. HP is always advertised over BHP since BHP is lower (always) than hp. Its a better selling point.

On Clublexus, people have been dynoing there modded IS300. In standard form, the IS300 makes 215hp. People with intake and other mods dynoed it and have been getting 180bhp.
This is confusing now when it wasnt before. I dont even know anymore whats advertised actually. http://forums.freshalloy.com/forum/images/icons/smile.gif But the fact is bhp and hp are different. http://forums.freshalloy.com/forum/images/icons/smile.gif

[This message has been edited by Infiniti (edited 06-30-2001).]<HR></BLOCKQUOTE>

HORSEPOWER

Definition: A unit of measure for quantifying power output. Invented by James Watt, the term was originally used to describe how much effort a horse exerted when lugging coal out of a coal mine. One horsepower was the amount of effort one horse put forth in raising 33,000 lbs. one foot in one minute. Engine horsepower ratings are determined on special equipment (See Dynamometer), and are usually expressed as so much "brake" horsepower (the amount of horsepower the engine actually delivers after internal friction and parasitic loses are taken into account).

Source: About.com (http://autorepair.about.com/autos/autorepair/library/glossary/bldef-306.htm?rnk=r1&terms=brake+horse+power)


[This message has been edited by noelsaw (edited 07-02-2001).]

[**DONOTDELETE**]

As for as the technical measurement or calculation of horsepower goes, this is a pretty good article: http://www.howstuffworks.com/horsepower.htm

There are various complications though. In mainland Europe, the term "horsepower" *is* different to Brake Horse Power, but only marginally. It is often called CV or PS (Pferdestärke). 1 PS is slightly smaller than 1 BHP. KiloWatt (kW) is an equivalent unit, with 1 bhp = 0.7457 kW.

To make matters worse, there are many different standards that companies use to measure their output, all giving slightly different calculations. The commonly-used standards for measuring output today include
JIS (Japan)
DIN (Europe, esp. UK)
EEC or EC (Europe too)
SAE (North America)

Most of these standards though would be roughly equivalent to the Nett outputs of a few decades back. Then outputs were pretty much either Gross or Nett, with Europe mostly quoting Nett values, and the US mostly quoting Gross values.

Coming back to the original query though, it is vary hard to say whether a mention of "hp" is meaning the same as bhp or PS (translates to horse power literally) or in fact whether it was measured at the crank or the axle. It is most likely in my humble opinion that it was being used interchangably with bhp and measured at the crank, but that is just a guess ;-)

Hope that helps!

Zak http://www.carfolio.com/

[Nismo]

Three different horsepower values are used to quote the performance of an engine:

(1) Indicated horsepower is the theoretical efficiency of a reciprocating engine, which is determined from the pressure developed by the cylinders of the engine;

(2) brake or shaft horsepower is more commonly used to indicate the practical ability of the engine, or the maximum performance, which is the indicated horsepower minus the power lost through heat, friction, and compression;

(3) rated horsepower is the power that an engine or motor can produce efficiently for sustained periods of time.

-quoted from Encarta

P.S.: These are technical terms, but for marketing purposes, a manufacturer may use whichever is the highest number, although most use BHP.