US E92 M3 less power than the Euro E92 M3

[335i black/red]

Is that true? It is the case w the Z4M, in Europe its 346HP and in US 330HP, and I heard the Euro version of the e92 M3 is 420HP and the US 414HP, as well as the catalytic converters imposed bu US emissions also slow the car down? does anyone have facts about this subject.

[The CSL]

The european figure given is normally 420ps (pferdstarke, German version of horse power, despite literally translating to horse power), which is 414bhp.

[swiss_cornholio]

Originally Posted by The CSL

The european figure given is normally 420ps (pferdstarke, German version of horse power, despite literally translating to horse power), which is 414bhp.

PS (German) == HP (US)
Only the BHP number is different (because obviously British horses are stronger than continental ones)

I.e. if the US HP number is different, the car is really less powerful.

[JEllis]

I believe US M5's and M6's have a few less HP than thier European counterparts due to an extra filter somewhere in the mechanicals. I have heard the extra filter is easily removed the power lost is restored. Its possible US M3's will have the same fate.

Jason

[joema]

The test standards are different between German DIN hp and SAE hp. Such differences exist even between various versions of the SAE test standard. E.g, the new SAE test stardard caused hp figures to drop, even though no vehicle changes were made. This mainly affected Asian mfgs, not German or American:

http://www.detnews.com/2005/autosins...A01-283759.htm
http://neptune.spacebears.com/opine/horsepwr.html

However the slightly optimistic DIN hp numbers vs SAE cause some to joke DIN = "Deutschland Invented Number".

It's likely much of the European vs US hp differences are due to variation in test standards, not actual engine hp differences.

[m_bazeepaymon]

i heard they messed with the torque though to make the speeds the same
(E46 M3)

[swamp2]

Originally Posted by JEllis

I believe US M5's and M6's have a few less HP than thier European counterparts due to an extra filter somewhere in the mechanicals. I have heard the extra filter is easily removed the power lost is restored. Its possible US M3's will have the same fate.

Jason

The US M5s and M6s do have an extra charcoal filter in the intake system that is easily removed. There was a bunch of discussion on m5board about this. Removing it is good for about the double that difference, about 12hp. http://www.m5board.com/vbulletin/att...5&d=1141945716 . I hope it is this easy to get 9 or so hp on the new M3, I suspect it will be. There is always the possibility that the engine will be rated 420 ps in EU and 420 hp in the US, that is the way it was for the RS4.

[E36325is]

Also the gasoline in the US have lower octane levels

[lucid]

Lower octain level does not reduce hp in an engine for a given compression ratio, which is mechanically fixed. UNLESS the European version has a higher compression ratio, the difference in the octane levels will not translate to hp differences. Octane is a measure of how much the fuel can be compressed before it self ignites and causes "engine knock". If the compression ratio is not set right for a given octane level, the engine might knock, and the ECU would respond by altering timing and so on, which might in return, result in lower hp, but that is a highly unlikely scenario since BMW engineers must have designed the engine and set the compression ratio for the lower US octane numbers. I can't imagine the European cars having a different compression ratio; it would be too much of a mass manufacturing hassle but who knows...

[Rick Hunter]

Originally Posted by swamp2

The US M5s and M6s do have an extra charcoal filter in the intake system that is easily removed. There was a bunch of discussion on m5board about this. Removing it is good for about the double that difference, about 12hp. http://www.m5board.com/vbulletin/att...5&d=1141945716 . I hope it is this easy to get 9 or so hp on the new M3, I suspect it will be. There is always the possibility that the engine will be rated 420 ps in EU and 420 hp in the US, that is the way it was for the RS4.

The Z4Ms also have this extra filter as well. I hope the new M3 won't be stuck with one, although I'm sure US emmisions laws will have the last word.

[Alumac]

If you have a question, utilize a question mark. Don't make it look like a statement. See the difference:

US E92 M3 less power than the Euro E92 M3?

vs.

US E92 M3 less power than the Euro E92 M3

[MisterBMW]

Originally Posted by Alumac

If you have a question, utilize a question mark. Don't make it look like a statement. See the difference:

US E92 M3 less power than the Euro E92 M3?

vs.

US E92 M3 less power than the Euro E92 M3

[skierman64]

It's interesting that the original poster lives in Egypt but yet is concerned about US HP numbers. I've been to Egypt, I certainly wouldn't own a nice car if I lived there. The driving is nuts.

[E90Fleet]

Originally Posted by E36325is

Also the gasoline in the US have lower octane levels

Not quite

USA pumps show PON

Euro pumps show RON

PON = [RON+MON]/2

So the lower number on american pumps are equivalent to the higher european numbers on the pumps

[E90Fleet]

Its likely the US M3 will have the carbon filter on the intake and possibly a more restrictive catalytic converter (similar to what E46 US M3 had )

[EBuyuk]

Originally Posted by E90Fleet

Not quite

USA pumps show PON

Euro pumps show RON

PON = [RON+MON]/2

So the lower number on american pumps are equivalent to the higher european numbers on the pumps

Your calculation method is very true. Just to give examples, in the US 93 octane is about 97-98 octane in Europe. However we have also 100 octane in Europe. Then again in the north-east US they also have 94 octane. But in the west coast the highest octane is 91 octane which is lower than in Europe anyway you look at it. (Not counting the very few gas stations in the US that sell 100 octane)

[gmund1948]

JetFuel please

[joema]

Originally Posted by lucid

Lower octain level does not reduce hp in an engine for a given compression ratio...

Actually, lower octane fuel will definitely cause lower hp and performance in the e46 M3. This was tested by Car & Driver in this article: http://www.caranddriver.com/features...r-premium.html

The e46 M3 has a separate acoustic knock detection sensor for each cylinder. If it detects knock, it will retard ignition timing to avoid this, resulting in less hp. Car & Driver found the difference was reproducible, measurable, and significant.

The e60 M5 and e90 M3 have an even more sophisticated knock detection system. Instead of using acoustic detectors (essentially microphones), they use ion current flow detection.

In this system, the spark plug itself becomes a combustion sensor. During the non-firing interval, the plug measures gas conductivity within the chamber, and a high-speed processor analyzes this -- all within milliseconds. It is much more sensitive and revealing of combustion characteristics (including but not limited to knock) than previous systems. More info from a similar aftermarket system developed for racing applications:
http://www.woodward.com/engine/smartfire.cfm?

Not all engines with knock detection exhibit such sensitivity to octane variation. However the higher performance M cars apparently do.

[lucid]

You are not quoting my response in full. I did say that it is possible to lose hp due to lower octane, but qualified that statement as a special scenario in the context of what we are discussing here. If you read it in full this is what I mean: If you supply an engine which is designed to operate with 91 octane fuel 87 octane fuel, depending on how you drive, you might cause engine knock, and the ECU will respond, and you will lose hp. However, if you supply an engine which is designed to operate with 87 octane fuel 91 octane fuel, nothing will change, and you will not see any hp gains. I am saying that BMW has probably designed the engine with and set the compression ratio according to the highest level octane available in the US (if that indeed has a lower octane rating then the fuel sold in Europe). If that is the case, there should not be any hp difference between the US and European models due to octane differences in the fuels available in the two continents.

[epiphone3]

Originally Posted by lucid

Lower octain level does not reduce hp in an engine for a given compression ratio, which is mechanically fixed. UNLESS the European version has a higher compression ratio, the difference in the octane levels will not translate to hp differences. Octane is a measure of how much the fuel can be compressed before it self ignites and causes "engine knock". If the compression ratio is not set right for a given octane level, the engine might knock, and the ECU would respond by altering timing and so on, which might in return, result in lower hp, but that is a highly unlikely scenario since BMW engineers must have designed the engine and set the compression ratio for the lower US octane numbers. I can't imagine the European cars having a different compression ratio; it would be too much of a mass manufacturing hassle but who knows...

The computer in modern BMWs will adjust the ignition timing with more advance if higher octane fuel is used... to a certain limit (I believe that is to 95AKI Octane number). The engine will therefore make more power with higher octane fuels to an extent, and be more fuel efficient.

[joema]

Originally Posted by lucid

...However, if you supply an engine which is designed to operate with 87 octane fuel 91 octane fuel, nothing will change, and you will not see any hp gains...

This is not always so. Some cars designed to operate on 87 octane will produce more hp on premium. In fact mfgs used exactly this technique (among others) to boost hp during SAE hp certification runs: http://www.motortrend.com/features/e...8_technologue/

This loophole was closed with the new revision to the SAE J1349 test procedure, which prohibited using premium octane fuel during certification runs in vehicles certified for regular octane.

The actual improvement in hp from using premium fuel in a car certified for regular will vary from car to car -- zero in some cases, a few hp in others.

One example: Charlie Baker, the head of 2003 Honda Accord project, has said in interviews the V6, although certified for 240 hp on regular octane, will produce about 250 hp on premium.

The bottom line is with newer, more sophisticated knock detection and engine control systems, hp may vary based on fuel octane. The more common case is engines certified for premium will produce less hp on regular. However in some cases engines certified for regular will produce more hp on premium.

[lucid]

If you get more hp from an engine by supplying it with higher octane fuel than it is designed to use that only means that the engine was NOT OPTIMIZED FOR PERFORMANCE. That would be the case for an Honda Accord, as the designers are keeping other variables in check and have a different intent compared to the M3 designers. We are talking about the M3 engine which should already be optimized for performance. Apart from that, the bottom line is the relationship between octane level and compression ratio; to truly take advantage of higher octane fuel, the compression ratio should be increased (apart from the minor tweaks you can do to engines which are not already optimized for performance.) We are not talking about any "modern BMW." Take an E46 M3, and fill it up with 100+ octane fuel. You will not see any significant improvement unless you change the cylinder piston geometry and alter the compression ratio.