BMW M3 and M4 to lose carbon fiber driveshafts
#1
BMW M3 and M4 to lose carbon fiber driveshafts
One of the current BMW M3 and M4's most distinctive features is their carbon fiber driveshafts. Sadly, the two BMW performance cars will become a little more mundane in the future, as the company announced it will transition the cars to steel driveshafts. The reason has to do with emissions.
BMW will begin adding a particulate filter to the exhaust system at some point in the future to stay compliant with stiffening emissions regulations. Carbon fiber driveshafts have a larger diameter and therefore take up too much space under the car. The "M-specific high-performance" steel driveshaft being used in its place is narrower enough to work.
BMW says that "the superlative performance and handling qualities" won't change with the use of the new driveshaft. We suspect that discerning drivers may notice a slight difference. Not only will steel add to the car's overall weight (however little), it will also represent more mass for the engine to move. This could mean the engine will be slightly less eager to rev. Of course, BMW could compensate for this by shedding weight elsewhere, possibly with a lighter flywheel or half-shafts.
Either way, though, this change still makes those M3 and M4 models produced in November 2017 and thereafter less special than those made before.
According to BMW, "for production-related reasons, this pre-enabling (of the new driveshaft for future emissions equipment) needs to be carried out universally." Presumably, this includes the United States, but as the announcement was made by BMW's global headquarters.
BMW will begin adding a particulate filter to the exhaust system at some point in the future to stay compliant with stiffening emissions regulations. Carbon fiber driveshafts have a larger diameter and therefore take up too much space under the car. The "M-specific high-performance" steel driveshaft being used in its place is narrower enough to work.
BMW says that "the superlative performance and handling qualities" won't change with the use of the new driveshaft. We suspect that discerning drivers may notice a slight difference. Not only will steel add to the car's overall weight (however little), it will also represent more mass for the engine to move. This could mean the engine will be slightly less eager to rev. Of course, BMW could compensate for this by shedding weight elsewhere, possibly with a lighter flywheel or half-shafts.
Either way, though, this change still makes those M3 and M4 models produced in November 2017 and thereafter less special than those made before.
According to BMW, "for production-related reasons, this pre-enabling (of the new driveshaft for future emissions equipment) needs to be carried out universally." Presumably, this includes the United States, but as the announcement was made by BMW's global headquarters.
#2
Lexus Fanatic
Well, the space/emissions argument may be true, but I'd bet the major reason for the change is cost. Carbon-fiber is significantly more expensive than steel.
#3
Super Moderator
With a base price just under $70k--exactly double the price of the standard 3 series--and a fully-loaded one right at $94k, cost is not the driver here. If it were, they would never have engineered the part in the first place.
My concern is that particulate filters are the bane of modern diesels, and I expect they're probably not much better on petrol engines.
My concern is that particulate filters are the bane of modern diesels, and I expect they're probably not much better on petrol engines.
#4
Lexus Fanatic
With all due respect, I think you're overdoing the base/list-price argument. I've seen the bean-counters hit vehicles with even six-figure prices. Not only that, but some of them can have atrocious quality control. Ironically, the most sloppily-assembled modern car I have reviewed was a blue 2008 BMW M3 coupe..
Last edited by mmarshall; 08-11-17 at 07:39 PM.
#5
Lexus Fanatic
With all due respect, I think you're overdoing the base/list-price argument. I've seen the bean-counters hit vehicles with even six-figure prices. Not only that, but some of them can have atrocious quality control. Ironically, the most sloppily-assembled modern car I have reviewed was a blue 2008 BMW M3 coupe..
#6
Super Moderator
On the flipside, have you ever actually seen a particulate filter? They're MASSIVE. Here's the one that's in my car:
For reference, that flange on the right side is a 3.5" exhaust pipe. This unit is directly attached to the low pressure side of the turbo. So the giant canister is behind and below the engine, not too far from the transmission output shaft.
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#8
Lexus Fanatic
edit: The $350 was a pair, not each...whew!!
Last edited by Johnhav430; 08-14-17 at 05:52 AM.
#10
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^^ me neither... The writer going on to say that it is one of the M3/M4's most distinctive feature? In addition, drivers being able to notice a few extra pounds? laughable. If this is really performance driven, then BMW will find a way to reduce the weight elsewhere and use CF on another body panel
#11
Lexus Test Driver
This is complete BS and very disappointing as I was planning to order 2018 with CompPack.
The CF driveshaft may not be noticeable but it is superior to a steel one and how the car was originally engineered. It was also hyped and promoted to death by BMW.
Makes no sense why they are doing it now with 2 years left in this generation.
They should lower the price (which will not happen) if this is their move, since the steel part is less than half of the CF one.
The CF driveshaft may not be noticeable but it is superior to a steel one and how the car was originally engineered. It was also hyped and promoted to death by BMW.
Makes no sense why they are doing it now with 2 years left in this generation.
They should lower the price (which will not happen) if this is their move, since the steel part is less than half of the CF one.
#12
Lexus Fanatic
Wonder if the CF roof will go away, that would be very obvious, unlike a driveshaft which cannot be seen when the vehicle is parked. I think the sedan got it for the first time in '15...
#13
IN CONTRAST, the LC500 took 4.6 seconds to get to 60, while the F80 takes only 4.0 seconds. The LC500 base is $92k.
At over $50k, it is pricey, but its also still fun to drive, it's RWD, the REx is brilliant, and it still has close to that BMW 50/50 weight distribution. There are more economical EVs out there, like the Bolt and the Volt, but after sitting in a friend's Bolt and then in my i3, the differences in driving experience is noticeable.
Back to the subject:
The M3/4 losing it's CF driveshaft is disappointing. I guess I can count myself lucky that I still have it. I'm not sure that the future hold for the M Division. The M3 was my dream car or a long time, but if the next gen M3 doesn't capture that old feeling that the M cars were known for, it might be time to move on to something that still does, like a Porsche.
Last edited by ragingf80; 08-15-17 at 12:10 PM.
#14
Lexus Test Driver
^
I think with Euro emissions - it will only get worse.
Rumors are new one will be AWD and Hybrid!
I test drove E92 M3 recently, that was probably last true ///M car. Values on them will be going up soon.
F80 is great and i loved mine but overall something is missing to make it great.
Although there is nothing new thats better under $100k, which is why im planning to get a 2018.
I think with Euro emissions - it will only get worse.
Rumors are new one will be AWD and Hybrid!
I test drove E92 M3 recently, that was probably last true ///M car. Values on them will be going up soon.
F80 is great and i loved mine but overall something is missing to make it great.
Although there is nothing new thats better under $100k, which is why im planning to get a 2018.
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