BMW tells Top Gear about upcoming M4

[swamp2]

Originally Posted by Uli_HH

Nope ... 1.495kg = 3.296lbs EU (-Empty) weight meens stock car including 68kg for driver, 44 kg (16 gal, estimate) for fuel, 7 kg for "cargo" !!!
~ 160kg less than the E92M3 !

Sure, I know that EU weight includes those additions, but you originally said "EU-Empty". I hadn't heard of that specification before. Surely that must mean something else other than just "EU"?

~160 kg (~350 lb) less than the E92 M3, of course on an apples to apples basis, simply is not going to happen. Want to place any friendly wagers on that?

[swamp2]

Originally Posted by caneaddict

Anyone know the unladen weight of the new 435i? BMW's site currently has only the GVW = 4505

http://www.bmwusa.com/Standard/Conte...fications.aspx

trying to understand the "baseline" from which we can compare the M4. I don't think it's as informative to compare weight of M4 to previous M3 because of the difference in engine, wheelbase etc.

There is a good post on various weight standards here. Unfortunately, there seems to be a description for GVW (maximum allowed operating weight with passengers and cargo and all fluids) but no exact formula/algorithm to back out curb or EU weight. That being said comparisons to the E92 M3 are certainly valid. However, the car being larger and likely having a heavier engine simply make and weight savings even more difficult.

[solstice]

Why compare to the E90 M3? It will share close to nothing with the F80. Forget that and focus on the F30 335i. It is much more similar in size and engine configuration and will share some parts. This is the car you should start out with and look at what can be done to reduce weight. The F30's chassi needs to be cheap enough to be used with profit for the entry level 3. The F80 has no such restriction. It will start at a price point way above the 335i. There is a LOT of room to add cost to the F80 chassi compared to the F30.

Way too much negative thinking in terms of weight. It's understandable though since BMW has been on a pretty constant disappointment streak lately. Just another reason why they will be willing to spend to make the F80 brilliant.

[swamp2]

Originally Posted by caneaddict

Anyone know the unladen weight of the new 435i?

Also in response to ^.

Directly from BMW documentation:

Unladen weight EU in kg:

335i: 1615 kg (3560 lb)
435i: 1600 kg (3527 lb)

Both with 6 cylinder and automatic/DCT transmission

The only way I can see that the 4 series is lighter than the outgoing 3 series is comparing 325i, 6 cylinder, MT vs. 428i, 4 cylinder, MT. The numbers in those cases are: 1505 kg vs. 1450 kg. But that isn't really apples to apples. It is because those are the most base models possible but it isn't because we want to know if the vehicle itself (independent of the engine) is providing weight gains or weight loss. The answer is clearly GAINS.

[swamp2]

Originally Posted by solstice

Why compare to the E90 M3? It will share close to nothing with the F80.

Because the cars are very, very similar in size, materials, constructions, electronics, really everything... Just because the parts are all new, doesn't mean they are essentially different.

[solstice]

Originally Posted by swamp2

Because the cars are very, very similar in size, materials, constructions, electronics, really everything... Just because the parts are all new, doesn't mean they are essentially different.

So you think the E90 M3 is going to be more similar to the F80 than the F30 335i in size, materials, construction, electronics and really everything? Sorry but it's obvious that for example the size, interior and engine is much more like the F30 335i than the E90. It seems like a much better reference point and much more likely to be F80's starting point when designing it than the E90 M3's older platform.

As a reference the F10 M5 is within 20 lbs of the 550i while it's almost 300 lbs between it and the E60 M5. It seems obvious that the platform plays a more significant role than it's predecessor.

Therefore I think it's better to forget about the E90 as a comparison for weight and instead look at the F30 335i and analyze what need to be added for strength, power, width, traction/LSD etc and what can be reduced with lightweight materials to get a better idea of what we can reasonably expect when M makes weight reduction a focus and it's main design objective. How good are they? We'll see.

[swamp2]

Originally Posted by solstice

So you think the E90 M3 is going to be more similar to the F80 than the F30 335i in size, materials, construction, electronics and really everything? Sorry but it's obvious that for example the size, interior and engine is much more like the F30 335i than the E90. It seems like a much better reference point and much more likely to be F80's starting point when designing it than the E90 M3's older platform.

As a reference the F10 M5 is within 20 lbs of the 550i while it's almost 300 lbs between it and the E60 M5. It seems obvious that the platform plays a more significant role than it's predecessor.

Therefore I think it's better to forget about the E90 as a comparison for weight and instead look at the F30 335i and analyze what need to be added for strength, power, width, traction/LSD etc and what can be reduced with lightweight materials to get a better idea of what we can reasonably expect when M makes weight reduction a focus and it's main design objective. How good are they? We'll see.

I mostly agree with this. In addition I've also posted just above apples to apples indications that the base model cars are also increasing in weight relative to their predecessors. And of course what matters in the end is the M4 weight vs. the outgoing E92 M3 weight. This increase is so bad (obviously) because making an M car from a base car always requires many components being stronger and hence heavier (engine, drive train, diff, wheels brakes, tires, suspension, etc.). With the base car itself being heavier it is all the more ground (i.e. COST) that needs to be made up for with materials that range from more expensive to MUCH more expensive.

And yes, we all know that right now at BMW and at BMW M, COST is KING. I've mentioned and argued it here (perhaps in excess...) but this is the primary reason for the major change in M engine architecture.

Cheers.