How much lighter is the M6??

[Wolverine]

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??

[JohnH]

Weight of M6 is 1710 Kgs which is 120 Kgs lighter than the M5 which is 1830 Kgs.

[Autobahnraser]

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).

[Wolverine]

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.

[9852147]

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!!!!

[Autobahnraser]

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.

[lasovan]

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.

[9852147]

btw, does anybody have the new m6 brochure and can upload it? please

[Wolverine]

Originally Posted by 9852147

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.

[Wolverine]

Here is the pdf link for the M6 Press Manual:

http://undergrad.nova.edu/kevin/m6.pdf