E90 vs E92 Listed Weights???

[Driver72]

OK, when it comes to the 335i the Sedan is listed as being a mere 23 lbs heavier than the coupe.
Both cars are listed as having the same aerodynamics.
Both cars have the same engine, tranny, options, etc.

Now I look at the E90 vs E92 M3

The M3 sedan is listed as being only 22 lbs heavier than the E92 M3.
But here's the kicker...
The E92 M3 (coupe) has the carbon fiber roof.
That roof is suppose to save 11 lbs in weight.
So if the E92 M3 had a steel roof like the E90 M3 and the 335i's it would be only 11 lbs lighter than the e90 sedan M3

How is it that if everything else is the same in the M3's as it is with the 335i is the M3 Coupe only 22 lbs lighter than the sedan WITH it's carbon fiber roof, when the weight difference of the 335i's (between sedan and coupe) is 23 lbs and the coupe has a STEEL roof??

Shouldn't the M3 coupe be 22 lbs difference PLUS the 11 lbs saved by the carbon fiber roof, making it overall 33 lbs lighter than the M3 sedan??

[Driver72]

What's also strange is BMW rates the 0-62 mph time of the M3 Coupe as being .1 second faster than the sedan.
That MAY be true because of the coupe being 22 (or should it be 33 lbs) lighter, but also because of coupe having a better weight distribution which may allow for slightly better off the line acceleration??

But if the sedan has better aerodynamics, as speeds climb, would the sedan actually have a slight acceleration advantage?


Seems to me it may just be all marketing hype for the coupe.
22-33 lbs weight savings alone isn't enough for the coupe to accelerate to 60 mph .1 second faster (maybe .051 and they rounded up).
But the 22-33 lbs weight saving AND the better weight distribution of the coupe (which puts 26 lbs more over the rear wheels and 48 lbs LESS over the front wheels) compared to the sedan, it very well could in fact accelerate to 60 mph .1 second faster.

But I'd be interested to see what BMW's acceleration statistics say for the 0-200 kph (0-124 mph) say for the two.
Because if the sedan really is a bit more aerodynamic, it should actually make up that .1 second difference to 60 and match the coupe's acceleration to 124 mph.

Just another one of those things that make you go hmmmm.
Yeah baby I went there.

Interesting tidbits I figured I'd share.

[mkoesel]

Originally Posted by Driver72

Shouldn't the M3 coupe be 22 lbs difference PLUS the 11 lbs saved by the carbon fiber roof, making it overall 33 lbs lighter than the M3 sedan??

Perhaps but there are probably many subtle differences beneath the skin of the two cars that actually tip the scale a bit more in favor for the E90 M3 over the E92 M3, vs. the E90 335i over the E92 335i. In other words the you can't assume that things vary in the same way between the two M3s as they do between the two 335i's.

In reality BMW USA weight figures are known to be pessimistic overall and also they are weighed in base configuration. So the margin for error is too great to quibble over these small variances anyway.

[Driver72]

True, option packages on the 335i can add as much as 60 lbs to the weight of the car.
With the M3, just adding the moonroof on the sedan adds about 30 lbs and will add 41 to the weight of the coupe (30 + 11) since you have to have the steel roof to get a moonroof.
And that's added weight in the worst possible place.

[sayemthree]

maybe the BMW wt listed for the Sedan does not include the moonroof. that could add 60 pounds.

[ersin]

It seems to me that the weight listed by BMW must be with all the options, fluids, gas, driver and three passengers. BMW says over 3700 lbs, yet people that weight their cars are getting 150+/- lbs less than this. The sedan will in general be heavier than the coupe but if you get a heavily optioned (pun intended) coupe it could be heavier than a stripped sedan. We need a thread with all of the reported, verified weights of the E90, 92 and 93 M3, including options and what was in the car when it was weighed.

As far as performance, the sedan does not seem to suffer any in the magazine reports. Both have done 0 - 60 in 4.1 seconds (best time) and all seem to be under 4.8, and in the 12's for the quarter. In the twisties they are both well mannered, confidence inspiring fun cars to play with. I believe as far as driving experience they are equal. The rear passenger area of the sedan is bigger, but the rear in the coupe is certainly livable. There are other differences (minor) that you can search for, but in terms of driving no difference.

[Blip Bavarian]

Are you sure that the coupe that they weighed had the CF roof?

[ersin]

Originally Posted by sayemthree

maybe the BMW wt listed for the Sedan does not include the moonroof. that could add 60 pounds.

I believe the weight difference is closer to 20 lbs.

[Serious]

fold down rear seats weigh the coupe down... in the sedan they are an option so arent factored into curb weight.

If you were to compare both cars in exactly the same options the sedan is probably going to be ~100lbs heavier then the coupe. which honestly isnt bad at all IMO.