Horse power /KW power figures by manufacturer

[TCJBOLDIE]

Are they still quoting at the flywheel or as IMO they should be quoting at the tyres power ??

 

[Aerial Andy944]

Probably at the fly as manufacturers know most buyers don't know the difference so want the greater headline figure. Bit like in audio where manufacturers quote PMPO watts instead of RMS watts.

 

[obi_waynne]

They all AFAIK quote the flywheel figure but there is usually a large variation in real power output from each car on the production line. Some companies like Porsche ensure all cars meet the quoted power figures but most mainstream cars do not.

 

[TCJBOLDIE]

I guess that if it was at the wheels HP then the makers would be inundated with owners who had their cars dynoed and the numbers were lower than claimed and almost nobody would have their motors tested on an engine dyno due to cost of removing and refitting .

So by quoting FW HP/KW's they can blame all sorts of things, transmission losses etc to explain away a low reading power figure.

 

[SLEEPER]

Manufacturers testing will be carried out with the engine mounted on a jig not on a car so flywheel is the only possible answer.

If it was done with the car on a dyno then the readings are most accurate on a hub dyno although they will often calculate flywheel bhp ( cos it's higher) even those it's an estimate.