iversonm

I don't think 3500-4000 lbs. unladen qualifies as light enough to be blown in the wind.

I still think the issue is tramlining, where the car follow imperfections in the pavement.

sleepyca31

Oh ya-why didnt I think of that-must just be total coincidence the 50 poeple on the board with the same complaint in the wind happened to be on the wrong road at the wrong time and just happened to be windy and when there is no wind we all happen to be on the right right-buddy obviously if it is only noticable in the wind it aint tramlining-half the people who concurred had non Runflats so save the same old blame the rfts for everything.

and where are you getting 3500-4000-the dude had a 530 as do I and unladen is 3300-3400-600 pounds is a big difference there bud. and it is not stricly weight-it is weight/area-which sis the kite effect-since both of these are variables in any lift equation-so if a tiny car weighed 2000 pounds that means nothing-the fact is the 5er is pretty big for 3400 pounds-

Man and people say I am slow-what a dunse'umm ya 3500 pounds aint that light" just such a dumb comment-obviously it depends on size of vehicle-didnt you get through HS physics for gosh sakes

monacobmw

The curb weight of a 530i is approximately 3400 pounds. The curb weight of an E-class is approximately 3900 pounds. If the 530i has greater surface areas, it will be blown around a bit.

The comments above state that a large car should not be blown around. If the car is light with large surface areas, you answered your own question. The problem could be solved with the placement of weights in the car, but that would kill the fuel mileage which is stellar. I also recall that the lightweight engine caused an closer 50/50 weight distribution, which is different than many other cars.

No one is saying that there is no defect in having a large car that blows around a bit, but I would not be so quick to jump on BMW to suggest that they should be going back to the drawing table to redesign the car for this issue.

sleepyca31

you do a search bro-I didnt make all 100 complaints-there were plenty of folks on here that vouched for this and had owned plenty of other similar sized weighted cars. Not saying it doesnt contribute but from memory there are a few things on the e60 missing to help this-such as any signifigant help with downforce on the car other than the straight design

One big one I remember is having a completely flat underside of the car-which is pretty much non-existent if you knwo a thing about car designs-you cant find a sports car without some help, especially on the underside or in addition usually elsewhere to help give some solid downforce-bmw has neither

iversonm

There are three keys just to the left of the letter 'M' on your keyboard that may help make you comments intelligible, but I somehow doubt it.

By the way, are you doing your residency with Jack Kevorkian?

iversonm

My point is that the car is not light enough to act like a "kite." The problem lies elsewhere, perhaps with tires or suspension.
The 5 series is average sized, and has a low center of gravity.

Since you mention the E class, lets look a little closer.

I don't have specs for the 530xi, so I'll assume the 528xi is equivalent. The 528xi is 3704 with an automatic. The MB E350 weight 3740.
(For the full range, the '08 528 manual trans is the lightest at 3505, and the 550 auto is the heaviest at 3968.)

The E class and the 5 are about the same size: The 5 is 191 in long, and 57.8 in high, and the E350 is 191 in long, and 58.4 in high. Considering their morphology is the same, their surface areas are roughly equivalent.

Should we think width is a factor, the BMW is 72.7 in wide, and the track is 61.3. The MB has a width of 71.7, and a track of 61.3.
As for weight distribution, the MB has a 51/49 weight distibution, and the BMW has between a 50/50 and 52/48 depending on the model.

In total, we have weight difference of 36 lbs. I can't see how 36 lbs. causes a wind problem.

The difference between the 550 and the 528xi is 264 lbs, roughly equivalent to one large American male in the car. One person should make it smooth out nicely if the surface area to weight theory is true.

Again, the problem may be springs, tires, ride height, suspension geometry, or difference in the steering mechanism between the i and xi.
I do not see compelling evidence that weight is a factor. I've driven minivans that are not battered by a crosswind, and they have massive surface areas in comparison, but only weigh a few hundred pounds more.