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Discussion Starter #1
Well, I did my research, and here's the scoop. Somebody should probably check my math.

The M6 is 120 kg, or 265 lb lighter than the M5. The listed 'Unladen' weight for the M5 is 1830 kg, and for the M6 is 1710 kg.

Here is the footnote from the M5 brochure:

"The figure specified includes a 90% tank filling plus 68 kg for the driver and 7 kg for luggage. Unladen weight applies to vehicles with standard equipment. Options and special equipment may increase this figure."

Here is the footnote from the M6 brochure:

"Weight of the car in road trim (DIN) plus 75 kg for driver and luggage"

To get what we americans call 'curb weight', which is the weight of the car with all fluids filled and no driver or luggage, we should subtract about 70 kg from the 'unladen weight' figures. (I'm figuring 5 kg for the 10% of fuel to top off the tank). This helps compare to american cars, where weights, and weight/hp ratio is done using curb weight.

So the curb weights of the cars are:

M5 1760 kg 3,880 lbs 3.52 kg/hp 7.76 lb/hp

M6 1640 kg 3,615 lbs 3.28 kg/hp 7.23 lb/hp

Bottom line is the M5 and M6 aren't as hefty as I'd originally thought, and the lb/hp of both M5 and M6 are better than I'd figured.
 

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unfortunatly you are wrong. bmw mentioned the power / weight ratio for the m6 at 3.5kg/hp. so the car won't be 120kg kighter than the m5.

also the difference between "normal" 5series and 6series is not more than ~30kg. and the m6 has not so many weight saving parts other than the roof.

but therefor the m6 will have a lower ?gravity? . and the carbon roof saves just a little weight over the standard roof (but not 90kg).
 

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When BMW quotes any figures they include the car at weight including 75Kg load and 90% fuel tank.

So when they said 3.5Kg/hp the weight used to come to that ratio included a 75Kg load and a 90% tank.
 

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According to my ifo:

545i=1705kg
645Ci=1690kg

So the difference is 15kg, but that's comparing 545i & 645Ci. I think we can't use the same logic for the M5-M6 comparison.

Note that the lightweight wheels of the M6 (1,8kg a corner lighter than the M5's) save more weight than the carbon roof. And we don't know about the other possible differences between M5 and M6 that could save weight.

We'll see.
 

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SuperBMW said:
When BMW quotes any figures they include the car at weight including 75Kg load and 90% fuel tank.

So when they said 3.5Kg/hp the weight used to come to that ratio included a 75Kg load and a 90% tank.
yes, that means 3.5 * 507 = 1775 and bmw quotes 1785kg for the m6, while the m5 is 1830kg heavy. diff is 45kg!!!
 

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Yes

From here http://www.germancarfans.com/news.cfm/newsid/2041214.009/page/7/lang/eng/bmw/1.html

"The BMW M5 Sports Sedan boasts a power-to-weight ratio of 3.5 kg:bhp, making it the benchmark in its class. Now, benefiting from its design and consistent lightweight technology, the M6 Coupe is another 45 kilos or 99 lb lighter than the M5. Featuring the same engine, therefore, BMW’s Sports Coupe comes with a sensational power-to-weight ratio of only 3.3 kg:bhp. This makes the BMW M6 one of the absolute leaders in the high-performance sports car market."


From www.BMW.co.uk
645i = 1695Kg
 

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Discussion Starter #8
9852147 said:
yes, that means 3.5 * 507 = 1775 and bmw quotes 1785kg for the m6, while the m5 is 1830kg heavy. diff is 45kg!!!
I got the 1710 figure from the M6 brochure. I can post it if you would like. Where are you getting the 1785 number?
 

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Wolverine said:
I got the 1710 figure from the M6 brochure. I can post it if you would like. Where are you getting the 1785 number?
Please post it if you can

1710 is 75 less than 1785, but you say the brochure says its 1710 including the 75Kg load

I wonder why www.BMW.de has official info for the M5 on the site but nothing yet for the M6
 

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Ok

Have finally gotten hold of the February editions of both UK CAR magazine and EVO

CAR: "The m6 is only 20Kg heavier than the 645Ci" so 1710Kg

EVO: "The M6 is 120Kg lighter than the M5", "the 19" forged wheels save 1.8Kg per corner" "carbon fiber roof saver 4.5Kg over 645Ci steel version"
 

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:2: :2:
NOW here is the real deal

Friend in Germany just e-mailed me the German Press release from BMW in December 2004

here is a direct quote

"Die Sport-Limousine M5 bringt es auf ein Leistungsgewicht von 3,5 kg
pro PS und setzt damit in ihrer Klasse den Maßstab. Bauartbedingt und dank konsequenter Leichtbau-Maßnahmen ist das M6 Coupé nochmals rund
45 Kilo leichter als der M5.:

AND

"Leergewicht nach EU1 kg 1785"



English: "The M6 is 45Kg lighter than M5"


So this is the final word as it is from BMW itself, the magazines used the weight less 75Kg load for M6 and weight including 75kg load for M5, thus comming to the wrong conclusion :confused3
 

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Discussion Starter #13
SuperBMW said:
Please post it if you can

1710 is 75 less than 1785, but you say the brochure says its 1710 including the 75Kg load

I wonder why www.BMW.de has official info for the M5 on the site but nothing yet for the M6
Unfortunately I don't have the paid version of Adobe Acrobat, so I can't post the pages. I'll try to load the paid version Monday. In the meantime, if anyone else can post the spec sheets from the back pages of the brochures, that would be great.

I have both the M5 customer manual and the M6 'media information manual in Adobe Acrobat files. On the last page of each manual, the title of the page is "Specifications", and they state the weights of the cars as:

M6:

Weight, Unladen (EU)* 1710 kg

*Weight of the car in road trim (DIN) plus 75 kg for driver and luggage

They also have the power to weight ratio listed as 4.6 kg/kw in the specification page, which is consistent with a 373 kw engine and a 1710 kg weight.


M5:

Weight, Unladen (EU)* 1830 kg

*The figure specified includes a 90% tank filling plus 68 kg for the driver and 7 kg for luggage. Unladen weight applies to vehicles with standard equipment. Options and special equipment may increase this figure

Here is another statement from the M6 brochure (52 pages long!)

"The BMW M5 Sports Sedan boasts a power-to-weight ratio of 3.5 kg:hp, making it the benchmark in its class. Now, benefitting from its design and consistent lightweight technology, the M6 coupe is another 45 kilos or 99 lb lighter than the M5. Featuring the same engine, therefore, BMW's Sports Coupe comes with a sensational power-to-weight ratio of only 3.3 kg:hp."

Well, if you take 3.5 kg/hp and multiply by 507 hp, you get 1,774 kg. Take 3.3 kg/hp and multiply by 507 hp and you get 1673 kg. You can't get to a 45 kg difference using 3.3kg/hp and 3.5kg/hp even with rounding error. Something's still not making sense here.
 

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From the German M6 press release ( English translated but google.com )

Geman: "Hinzu kommt ein Leergewicht von nur 1785 Kilo, Idealmaße und Idealgewichte in einer besonders reizvollen Verbindung"

English: "In addition an unloaded weight of only 1785 Kilos, ideal mass and ideal weights comes in a particularly delightful connection"


German: "Achslastverteilung und Schwerpunktlage erhöhen die Agilität des nur 1785 Kilo leichten M6 beträchtlich. In der aktiven und passiven Sicherheit liegt der M6 dennoch ohne Einschränkung auf dem hohen Niveau des Basis 6ers"

English: "Axle load distribution and position of the center of gravity increase the Agilitaet of the only 1785 Kilo easy M6 considerably. In active and passive security the M6 is nevertheless without restriction on the high level basis of the 6ers"

German: "Die Sport-Limousine M5 bringt es auf ein Leistungsgewicht von 3,5 kg pro PS und setzt damit in ihrer Klasse den Maßstab. Bauartbedingt und dank konsequenter Leichtbau-Maßnahmen ist das M6 Coupé nochmals rund
45 Kilo leichter als der M5"

English: "The sport sedan M5 brings it on a weight per horsepower of 3,5 kg per HP and sets thereby in its class the yardstick. Design conditionally and owing to consistent lightweight construction measures the M6 Coupé again approximately 45 Kilos lighter than the M5"


Technische Daten.
Leergewicht nach EU1 kg 1785



Now looking at the weights without the 75Kg load

M5 1755Kg
M6 1710Kg

M5 1755 / 507 = 3.461 so rounded to 3.5

M6 1710 / 507 = 3.372 Rounded down to 3.3 ?
if it were 1710-75=1635 then 1635/507=3.224 which cant correctly be rounded to 3.3


I believe BMW Germany, as BMW USA has made a number of incorrect statements before. Like recently saying the M3 competition package has forged wheels when they are not, saying the M3 Competition Package has the same wheels as the CSL, when the CSL has 8.5J front wheels and the Competition 8.0J
 

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Discussion Starter #17
SuperBMW said:
From the German M6 press release ( English translated but google.com )

Geman: "Hinzu kommt ein Leergewicht von nur 1785 Kilo, Idealmaße und Idealgewichte in einer besonders reizvollen Verbindung"

English: "In addition an unloaded weight of only 1785 Kilos, ideal mass and ideal weights comes in a particularly delightful connection"


German: "Achslastverteilung und Schwerpunktlage erhöhen die Agilität des nur 1785 Kilo leichten M6 beträchtlich. In der aktiven und passiven Sicherheit liegt der M6 dennoch ohne Einschränkung auf dem hohen Niveau des Basis 6ers"

English: "Axle load distribution and position of the center of gravity increase the Agilitaet of the only 1785 Kilo easy M6 considerably. In active and passive security the M6 is nevertheless without restriction on the high level basis of the 6ers"

German: "Die Sport-Limousine M5 bringt es auf ein Leistungsgewicht von 3,5 kg pro PS und setzt damit in ihrer Klasse den Maßstab. Bauartbedingt und dank konsequenter Leichtbau-Maßnahmen ist das M6 Coupé nochmals rund
45 Kilo leichter als der M5"

English: "The sport sedan M5 brings it on a weight per horsepower of 3,5 kg per HP and sets thereby in its class the yardstick. Design conditionally and owing to consistent lightweight construction measures the M6 Coupé again approximately 45 Kilos lighter than the M5"


Technische Daten.
Leergewicht nach EU1 kg 1785



Now looking at the weights without the 75Kg load

M5 1755Kg
M6 1710Kg

M5 1755 / 507 = 3.461 so rounded to 3.5

M6 1710 / 507 = 3.372 Rounded down to 3.3 ?
if it were 1710-75=1635 then 1635/507=3.224 which cant correctly be rounded to 3.3


I believe BMW Germany, as BMW USA has made a number of incorrect statements before. Like recently saying the M3 competition package has forged wheels when they are not, saying the M3 Competition Package has the same wheels as the CSL, when the CSL has 8.5J front wheels and the Competition 8.0J
I think the correct numbers are M5 1755, M6 1710. These are contradicted by the spec on the m6 on the last page, and as you point out, the 3.3kg/hp is incorrect, but my guess is these are the real numbers.

It really surprises me that the Germans would permit errors like "3.3 kg per hp" when this is simply incorrect. As any engineer that has finished their first year in school knows, 3.372 is 3.4, not 3.3.

If 45 kg is the weight difference, it's not very impressive IMO. They sure make a big deal about their emphasis on weight reduction, and you would think they could have done a better job.
 

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Well the M5 is 125kg heavier than the 545i (1830kg vs 1705kg)

The m6 though is only 95 Kg heavier than the 645i ( 1785kg vs 1690kg )

So they shaved 30Kg off the weight increase

That is not easy to do

There are hardly any places to shave more weight, the wheels are as light as they can go, the roof is carbonfibre, the fenders and boot are thermoplastics. The front is already heavier than the back 54/46 weight distubution.
So you need to lighten the front first, and only way to do that is lighten the engine, which will cost big $$$$$$$$$

Only other way to save weight is to remove the sound insulation and rear seats
 

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One way to save even more weight ( and im not refering to anyone in particular ), is for the drver to loose weigth themselves

Im shure a number of owners could stand to loose a few pounds themselves, thus increasing perforance :D
 

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SuperBMW said:
There are hardly any places to shave more weight, ......
Good points, completely agree. Which makes the M6 CSL more of a joke. You end up with a large chassis stripped of all its defining luxury features, which a large coupe should always have. I think BMW needs a new line or a super car to be the real pure breed sports car. (For example, Benz has the CL and SL classes, but BMW is missing something to combat the SL and others of that size).
 
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