i having a conversation with a friend of mine.
he tells me that BMW has a history of claiming less horsepower
on their vehicles than they really have and that in reality,
mini coopers may actually dyno higher than what is said to be
on paper.

anyone have an thoughts on this? it'd be great if it were true.

 

BMW usually underates their engines.

The current 335/135/535 are listed at 300hp but dynos show them to be closer to around 325-330hp.

I believe the MCS has been dynoing a little higher than what it should based on the listed HP. I believe there are some threads about it here somewhere.

 

Hmmm... Why would they claim lower?? If the hp was higher wouldnt that be a reason for buying?? Sounds fishy to me

 

alot of manufactures do this. Z06 is an example.

 

But why?

 

I am not sure that it matters since it comes down to how you use the power you have . Take a look at Mini's racing history of destroying cars on the race track that have much more power. For example, I have witnesses the total destruction of a field of authentic 427 Cobras and big HP 60's Corvette's at the hands of a tiny Lotus 26R at Road America's historic races and it made a believer out of me.

 

One possibility is that in Europe if I remember correctly your insurance and yearly registration fees etc. are tied to horsepower...

Lower hp less you pay...

 

One thing manufacturers don't want to do is tell you some high HP number and then suffer the negative backlash when they are proven incorrect via independent reviews/analysis. This happened with one of the auto manufacturers and ended up with them offering to buy the cars back / offering incentives to buy another model. Does anyone remeber this and which manufacturer it was??

 

In an effort to standardize horsepower ratings, the SAE passed a new horsepower rating standard, specifically J2723, to complement the existing standard, J1349. This effort standards testing procedures across all manufacturers, so that horsepower ratings make sense, i.e. a Ferrari that produces 300 hp is the same power as a Hyundai that produces 300 hp.

So in fact, BMW has been overrating their engines. As an example, a BMW engine with 300 hp pre-J2723 is making only 285 hp with the new standard. Because small shops have yet to adopt the new standards, their procedures are pre-J2723. A current engine that BMW rates at 285 hp, is being dyno'ed at 300 hp.

Hope that makes sense?

 

A few years ago the Honda Accord 3.0 V6 was downrated, the Tacomma 4.0 V6 was downrated, the Mazda Miata was downrated. This was around 2004-2005 time frame I believe. There may of been a few other Japanese makes but can't remember which. I believe Mazda is the only company that offered to buy back. I also recall that some of the General Motors cars were found to be under rated in HP.

 

I know the Fox body 5.0 Mustangs were rated 220 or 225 hp and testing later showed them to have less. Big stink after that happened.

 

I remember Porsche offering the same deal kinda under the table and therefore unofficial. In Germany the title lists the HP which puts you in different tax rates when it comes time to annually renew your registration. When you upgraded to additional 20 HP or so the title still read the standard tested HP under perfect conditions.

 

That would be Mazda and the RX-8 when it first came out.They overated the horsepower figure and they offered to buy the car back or give some sort of financial credit to those that kept their cars.

Back to the OP:
The underrating of engines goes back to IIRC the early 1970's when insurance companies were beginning to hit owners with higher insurance rates with higher horsepower.So the manufacturers began to underrate the engines due to that.

Although today seems to be the opposite in some respects with the current "horsepower wars" revival.