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Discussion Starter #1
What is the weight savings of the M6 over the M5?? I've heard everything from 45 to 120 kg. It seems like BMW is making a big deal over the weight savings on the M6, but 45 to 120 kg doesn't sound like much to me.


They list the weight in the brochure as 1710 kg:

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

If I subtract 75 kg from 1710, I get 1635 kg, or 3604 lbs. Is this right??
 

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According to the German brochures the M6 (1785 kg = 1710+75) weighs only 45 kg less than the M5 (1830 kg). BMW AG doesn't make a big deal over the absolute weight savings; they feel proud about 'where' the weight has been reduced (much lower centre of gravity, less overhang in corners compared to the M5, aside from a better drag and shorter wheelbase).
 

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Discussion Starter #4
Well, I did my research, and here's the scoop.


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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autobahnraser is right.

weight for m6 is 1785kg and for the m5 1830kg. these are "EU-weights" (including 68kg for driver, 7kg for luggage and 90% filled fuel tank (63l) )

so weight without driver, luggage and empty tank is:
1647 and 1692kg

weight with 100% filled tank is:
1717 and 1762kg


as you see, the m6 is just 45kg lighter. and definately NOT 120kg!!!!
 

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Have a look at the 2 specs sheets below. The first one (Power Car) says Leergew. (unladen weight) = 1710 kg; the second one (official BMW M6 brochure) says Leergewicht EU (unladen weight EU) = 1785 kg. The reason for this discrepancy is that there are 2 possible unladen weight figures, the "pure" one and the EU one that includes additional 75 kg for driver, baggage and fuel.
 

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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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Discussion Starter #9
9852147 said:
btw, does anybody have the new m6 brochure and can upload it? please
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. Possibly they misprinted the weight in the spec sheet - wouldn't be the first time.
 

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I can't imagine that big a difference in daily driving (provided the M5 isn't full of people).

Absolute performance numbers will be slightly better for the M6, but probably not by the big margin everyone (including BMW) thinks. The M6 will feel faster due to different suspension settings, exhaust etc.
 

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Have people considered whether existance of the optional sunroof on the M5 accounts for the weight difference discrepancies? I suspect the 45kg difference is for an M5 w/o sunroof.

Tom
 

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Discussion Starter #14
Ashok Arora said:
I can't imagine that big a difference in daily driving (provided the M5 isn't full of people).

Absolute performance numbers will be slightly better for the M6, but probably not by the big margin everyone (including BMW) thinks. The M6 will feel faster due to different suspension settings, exhaust etc.
I have to agree that there won't be much difference in actual numbers. Given that the weight difference between the two is 45 kg, that equates to about 10 additional hp in acelleration testing. Possibly the M6 will 'feel faster', but line up the M6 and M5 for a race, one with a 50kg woman driving the M5 and put a 100 kg man in the M6 and the M5 has the better power-to-weight ratio.

I'm dissapointed that 45 kg is the best BMW can do for a smaller car with mini-back seats. How about a 550 hp engine???
 

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Wolverine said:
I'm dissapointed that 45 kg is the best BMW can do for a smaller car with mini-back seats. How about a 550 hp engine???
Agree. But economics comes in. That's why they can launch the M6 six months after the M5 using the same V10 and recoupe the R&D costs without spending anymore money. I read the V10 R&D costs had blown the allocated budget (which is good).

The real question at the end of the day is whether one needs an uber-sedan or a coupe.
 

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wolverine, the m6 is not that much smaller than the m5.

the dimensions of the 5series are 4.84m length, 1.47m height and 1.85m width. the 6series is 4.82 / 1.37 / 1.86

so the 6series is only 10cm lower, but that does not make a big difference in the overall weight...
 

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Discussion Starter #17
I'm really trying to justify paying some $15-20Kmore for the M6 over the M5. It's tough to do if you look at it logically. Of course, the same can be said of the 645 over the 545.
 

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Wolverine said:
I'm really trying to justify paying some $15-20Kmore for the M6 over the M5. It's tough to do if you look at it logically. Of course, the same can be said of the 645 over the 545.
Do you need the practicality of a sedan? I don't, as I intend to make the M6 coupe my personal daily driver, not expecting to carry passengers. A bit of a fun car in town during the week. And I do think the 6 looks better than the 5 (inside & outside) and more exclusive. Other than that, I can't think of anything much else between them.
 

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Discussion Starter #19
M6 Forever said:
Do you need the practicality of a sedan? I don't, as I intend to make the M6 coupe my personal daily driver, not expecting to carry passengers. A bit of a fun car in town during the week. And I do think the 6 looks better than the 5 (inside & outside) and more exclusive. Other than that, I can't think of anything much else between them.
I've got to agree with you on the looks, inside and out. The 6 is a beautiful car. I'm struggling right now between the M5 and M6. I'm first on my list for the M5, but the M6 seems to be just a little bit better in every respect except a back seat. Hmmmm....I could always use the Acura or the Volvo if I needed a backseat...
 
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