swajames

Yep, there's no doubt the 550 is heavier. The point under issue was really what the net impact was of that extra weight. Some claim it's all up front (and thus the 550 should be nose-heavy, and have an increased tendency to understeer). I maintain the 550 is, relatively speaking, identically balanced.

BMW's own numbers bear that out - the weight distribution numbers I quoted in my earlier post are straight from BMW. With a steptronic, the 550 actually has a marginally better weight distribution than the 535...

Edited to add the numbers from my earlier post:

535 - weight distribution is 51.8% front/48.2% rear

550 - weight distribution is 51.7% front/48.3% rear

These numbers assuming both cars have Steptronic. Uheenada has posted the numbers for the MT, and again they show almost identical weight distribution.

Brit_in_NJ

uheenada, Although I agree with your numbers I don't think that they engineer in "dead weight"

CWS530

But which car would handle better if a Republican, atheist, lesbian (who wants to get married and had been artificially inseminted) was giving birth in the back seat? Obviously something should be done with the umbilical cord blood, but her parents are both illegal immigrants. 535 or 550?

uheenada

Well, you could argue with that, but i think it could be really dead weight since it's cheaper to add
dead weight somewhere on real axle than relocate other parts to balance out. Or since 550 and 535 do not
share drivetrain parts at all so it could be those weight. The dead weight or ballast(that's what a dead weight called in Formula 1)
came to my mind first when i was thinking about balance. It's very true that f1 cars purposely build chassis underweight(of min weight reg)
then add weight ballast to adjust the handling/balance of the car. So I think we can't disregard this as it's very simple ye very effective method to balance it out.

Anyway, whatever it is, they spread out the extra weight. That's all it matters!!

Brit_in_NJ

Again I totally missed the post with those numbers I'm assuming they are on the BMW website somewhere? I know the weight is not "up front" based on those numbers and that I passed high school physics. I just can't get the numbers to distribute that weight the way BMW claims, not that I am doubting them just doubting my guesses. However that extra weight however it's distributed at rest will shift to the front of the car under braking to have an adverse effect on handling. Now is that weight shift compensated for by the suspension? To some extent yes but if the numbers from Edmunds that I quoted in an earlier post are accurate then not entirely. Having not driven both cars I would just guess that the 535 feels quicker going into and around the corner but that the 550 will feel quicker coming out of it, maybe you would also get brake fade earlier with the 550 than the 535. The only way to tell is by putting a consistent driver in both cars and compare.

Brit_in_NJ

The drive train is different (I checked realoem.com) so I would presume the weight is in those components. For a road car it would be overkill to add dead weight whereas there are lots of reasons to build an F1 car underweight. If BMW were adding dead weight I think that almost 50/50 weight distribution they claim in the commercials would be spot on.

Brit_in_NJ

42

pennetta

Guys we are way off base here and don't get sidetracked with weight distribution. I have two questions that you are ignoring:
1. If you added 260 lbs 10 feet above the car, maintaining your weight distribution, would the car still handle as well or worse?
2. If you added 260 lbs to a 535, maintaning your weight distribution, do you think it would handle better or worse?
Just intuitively think about this.

I was an engineer so I have an unfair advantage, but you are confusing yourselves. Why do you think the e60 suspensions are made of aluminum, why is the hood aluminum, the fenders, etc,etc. Its to lessen the weight. Trust me, less weight makes better handling cars, better stopping cars and better accelerating cars.

And you would never add dead weight. The brakes are the same, the transmissions are different but probably weight similar, the exhaust would weight more but its light weight stainless steel, the 550 has lighter weight non-runflats. The majority of the weight, over 225 lbs of it and probably more, is in the engine.

uheenada

It's very hard arguments with either side are very convincing.
What I thought is that, we are comparing road cars with stock set up.
So, the chassis, suspensions, engines, and any other parts are not being pushed to its limits.
Bmw simply put bigger brakes/rotors to compensate the heavier weight, firmer suspension etc to
counter attack the weight "while" 535 simply doesn't need those and got smaller brakes/rortors
less stiff spring,shocks etc(for money saving, it can't just be the engine to cost $8000 more).
So, BMW created each model to equal(exception of M). That's the key point.
I can safely say as long as we are comparing stock vs stock you won't see the difference.
And for the numbers you refer to, it could be that 550i tires are a bit worn out(it's a demo car after all where each car mag borrows and edmunds wasn't first in line)
or even with same identical cars perform varies little so it could be 550i they tested was low baller who know? The fact is .01g(i think i can't remember) is too small
margin to conclude 535 is handles better.

However, if we start modding the cars heavily where it's track only car, then no doubt 535 will be better chassis to bet on.

So, the extra weight doesn't come into equation until the car is maxed out cuz simply 550i can have better suspension/brakes
whatever to compensate the extra weight.
I hope you get my drift

pennetta

Thank you...LOL!