bm323

Quote:

Originally Posted by Shebs

It is amazing how you refer to my statement in post 27 "not only did the coefficient of drag get worse but also the frontal surface area got bigger" then you claim that I only referred to Cd and not drag force, while the drag force itself is proportional to Cd multiplied by frontal area. Next time I will start with the equations .Did I say you only referred to Cd??

It is not a seperate matter as I explained above. If by euro requirements you mean pedestrian protection then no. Any basis for this? The shape of the (the hood, the fenders, the bumpers, wind shield, etc.) determines its Cd. The frontal area is a the projected area of the cars front view on a 2D plane. To put it in simple terms, it is like taking the shadow of the car from a very big lamp behind the car to a wall in front of the car. The shadow area (in m^2 or ft^2 or in^2) will be the frontal area. Multiply that by Cd and you get an idea of the aerodynamics and drag force on the car.

You are going in circles here . First of all I knew that as a car has different Cds with different engines and versions when I was around 15 years old (and I don't have the time to explain why), so I did not assume that all E60s were 0.27.

Facts:
E34: Cd from 0.32 to 0.34
E39: Cd from 0.28 to 0.31
E60: Cd from 0.27 to 0.30
F10: Cd from 0.28 to 0.?? (Depending on the new M as I explained before, I personally expect 0.30+)
F10 Frontal Area is bigger than E60 (for whatever reason which is not the discussion point here)

Conclusion:
The BMWblog article author was mistaken to refer to the improved aerodynamics of the F10

The BMW F10 remains a great call in all aspects. You have to accept that aerodynamics were not improved however .

Did you not say that the Cd for the E60 is worse than the f10?? See below.

Quote your post #27 " Not only does the F10 have larger frontal surface area, but it also has a worse coefficient of drag adding to aerodynamics deterioration."

Quote:

Originally Posted by Shebs

Cd is worse for the F10 when compared to E60 on average (if we add all the drag coefficients of the different versions of the E60 and divide them by the number of versions and do the same for the F10). Regardless of this fact, even if we assume that Cds are equal to your own liking, the frontal area A is still larger in the F10 than it is in the E60. Consequently Cd * A will be higher. Thus the drag force will be higher. Therefore the statement made by the Bmwblog article author where he refers to improved aerodynamics is wrong as I pointed out in post #27.

Now, are you saying that it is justified to say that the Cd for the F10 is worse than the E60, when only the E60 523i is 0.01 lower, and the F10 528i, 535i and 550i has the same Cd as the E60???

Shebs

The BMWblog article (that you posted) author was mistaken.

Every time you wake up in the morning and start your engine, you have to remember that the E60 had better aerodynamics than your F10. I hope you can live with that fact HAHA HAHA HAHA (evil laugh) .

bm323

Now good that you have made your position clear although remaining evasive you have still not grown up by refusing to admit that you were erroneous in your statement that the F10 has a worse Cd than the E60, and instead persisted to mislead by focussing on a separate point that was never in issue. Also, you persisted in saying that your E60 523i (bought in 2006) has a Cd of 0.27 but the specs of the 2005 E60 523i has a Cd of 0.28 and the 2007 has a Cd of 0.27. (You have not provided any link to the Cd for the E60s in particular for your 2006 523i although requested to).

Now, having placed this child in the corner let me deal with your red herring non issue; check my posts whether I've ever made any issue of better/worse aerodynamics or drag force. The F10 (except for the 523i) has the same Cd as the E60, and we all know that the F10 is larger (and based on the larger frontal area as you defined it ), it clearly would have a higher drag force. Did you know this only when you were 15 ie the same number (ie Cd here) multiplying a higher number A(area) would of course give a higher number

kscarrol

Wow, we need to find hobbies for bm323 and Shebs...

bm323

This is a fair view haahahahaha (not evil laugh )

BigMike

No use talking about the "coefficient of drag get worse cuz the frontal surface area got bigger" as BMW went to making pug-nosed fronts because of EU safety regulations... I guess they just had to go there.

As for me, the F10 ain't that bad... I'd just might get one if they put out some real nice rims to go with it.

Shebs

Drag force governing aerodynamics in general is proportional to both the coefficient of drag and frontal surface area.

Coefficient of Drag depends on the aerodynamic profile of the car. The Cd of the F10 is worse on average than that of the E60 due to the EU safety standards pug-nose as you mentioned and BMW had to go there.

The frontal surface area depends on the dimensions of the car. It got worse because the F10 dimensions so it is not related to the shape of the car.

So they are two seperate things. Hope this explains the matter .

Shebs

I am not sure that the Cd of the 523i in 2006 was 0.27 as I might have checked the BMW sight at 2006, 2007, or 2008. It might be also that it was the Cd of my old 520i http://www.carfolio.com/specificatio...ar/?car=110198. I could not find a link to the 2006 523i, but this is not the issue.

The issue is that you are trying to dodge facts .

In general, the F10 has a higher Cd than that of the E60 it replaces. Add to this its larger frontal area and you will end up with unimproved aerodynamics. The Bmwblog article that you posted contained erroneous facts.

You still have to live with that fact every time you start your engine in the morning .

I am afraid that I will have to live with the same fact as well, when I buy the F10 .

By the way, we are starting to look ridiculous in the eyes of other members. We can take it to a private conversation if you would like.

Shebs

To further add to my previous post, from Carfolio.com (Cx is the aerodynamics governing factor = Cd * A):

520i
2002 E39 520i
Drag coefficient 0.280
Frontal area 2.17 m2
Cx 0.61 (which is Cd x A)

2003 E60 520i: (I ownded one of those)
Drag coefficient 0.260
Frontal area 2.26 m2
Cx 0.59 (which is Cd x A)

523i

E39: No data

E60 2005 BMW 523i aerodynamics
Drag coefficient 0.280
Frontal area 2.26 m2
Cx 0.63

2007 BMW 523i aerodynamics
Drag coefficient 0.270
Frontal area 2.26 m2
Cx 0.61

E60 2007 BMW 523i Automatic aerodynamics
Drag coefficient 0.260
Frontal area 2.26 m2
Cx 0.59

F10 2009 BMW 523i Automatic aerodynamics
Drag coefficient 0.280
Frontal area 2.35 m2
Cx 0.66

530i

E39 2002 BMW 530i Automatic aerodynamics
Drag coefficient 0.300
Frontal area 2.17 m2
Cx 0.65

E60 2003 BMW 530i Automatic aerodynamics
Drag coefficient 0.280
Frontal area 2.26 m2
Cx 0.63

E60 2007 BMW 530i aerodynamics
Drag coefficient 0.270
Frontal area 2.26 m2
Cx 0.61

F10 2009 BMW 528i aerodynamics
Drag coefficient 0.280
Frontal area 2.35 m2
Cx 0.66

535i
E39: Did not exist as turbocharged engine

E60 2007 BMW 535i (US) aerodynamics
Drag coefficient 0.290
Frontal area 2.26 m2
Cx 0.655 - I calculated that one

F10 2009 BMW 535i Automatic aerodynamics
Drag coefficient 0.290
Frontal area 2.35 m2
Cx 0.68

550i

E60 2007 BMW 550i aerodynamics
Drag coefficient 0.280
Frontal area 2.26 m2
Cx 0.63


F10 2009 BMW 550i aerodynamics
Drag coefficient 0.300
Frontal area 2.35 m2
Cx 0.71

If you see the analysis above you will see that the E60 had better aerodynamics than both the E39 and the F10. Please provide any data that proves otherwise.
I do not care if you believe me or not, but I am sure that my car Cd was 0.27 when I bought it. You were not able to refer to any sources that proved that the 2006 523i Cd was otherwise (you only referred to 2005 and 2007), and I challenge you to do so. The analysis above explains why the wind noise was higher in the 523i F10 that I test drove. It is because its Cx is higher by 4.7% than the E60 2005 523i and 11.8% than the E60 2007 Automatic 523i. Also your Cx for the F10 535i is higher than that for the E60 2007 535i by 4%.

Now dodge that .

bha7176

Yeah! Go SHEBS! I like you man. Way to back up your info with facts.