[Maxdog]

Does it actually apply the brakes or just light up
In dash? The other day going slow I was looking at screen and it felt like the brakes jammed on. I was going very slow in traffic and a car I front of me

[Damon44]

Originally Posted by Maxdog

Does it actually apply the brakes or just light up
In dash? The other day going slow I was looking at screen and it felt like the brakes jammed on. I was going very slow in traffic and a car I front of me

This technology is incredible at saving our lives and cars/
I personally thank the driver assist packages everyday.
As I get older and lose rotation in my neck, the warnings and cameras have become increasingly beneficial.
There ability to react instantaneously without fatigue or inattention is remarkable.

[Mike_L]

I believe its capable of braking. The manual isn't really clear. I think it warns you first and then slows down to lessen any impact.

[x5mad]

The manuals are not very clear on this and the SA are no better.

From what I have read my understanding is as follows:

There are essentially 2 systems, one with active cruise control and one without.

1. With ACC you get warnings plus the car is capable of braking for you.

2. Without ACC you get warnings but the car will NOT brake for you. In an emergency situation the car will prime the brakes but you must initiate the braking yourself.

[Maxdog]

Thx for the info I don't have acc it must of been the stalling clutch was engaged

[cinetic]

So I had DA, DA+ and ACC on my F31. In conditions where it could tell a collision was imminent, you'd hear the collision beep and see it on the HUD. Then the car would prep the braking system so that when you applied the brakes, you'd basically lock them up for a quick second and almost stop with like 10% of braking pedal force.

[snowghost]

Originally Posted by cinetic

So I had DA, DA+ and ACC on my F31. In conditions where it could tell a collision was imminent, you'd hear the collision beep and see it on the HUD. Then the car would prep the braking system so that when you applied the brakes, you'd basically lock them up for a quick second and almost stop with like 10% of braking pedal force.

Nice to know.

[rics70]

Actually the system will apply the brakes for you if it feels the collision is imminent. I have it brake the car in slow traffic, it beeps first the next thing is start braking.

[Mobster1983]

Originally Posted by rics70

Actually the system will apply the brakes for you if it feels the collision is imminent. I have it brake the car in slow traffic, it beeps first the next thing is start braking.

This. I have had the car SLAM on the brakes automatically when the car in front of me did a sudden stop at the exact moment I turned my head to check behind me before switching lanes. it does give a loud warning first, which has in a few cases given me that extra split second to hit the brake myself.

I have ACC and all the other options. What less options do I cannot say.

[ah3]

Originally Posted by rics70

Actually the system will apply the brakes for you if it feels the collision is imminent. I have it brake the car in slow traffic, it beeps first the next thing is start braking.

Do you have ACC?

[menkupalme]

I think it warns you first and then slows down to lessen any impact.

[stormlv]

Sounds the alarm, pretensions the brakes and eventually applies the brakes if the driver doesn't do anything.

Experienced all of those on mine (sensibility set to high)

In any case, always drive as this system is not there

IIHS has tested this (http://www.iihs.org/iihs/ratings/veh...s-4-door-sedan) and found that:

In the 12 mph IIHS test, impact speed was reduced by 7 mph.
In the 25 mph IIHS test, impact speed was reduced by 6 mph.

Still something...but it's a far cry from what Volvo does now

German comparison of multiple vehicles...

Fifth Gear comparison between Volvo, Mercedes and VW

Let's hope BMW takes notice and updates the system in future versions.

In any case, anything's better than nothing, and the alarm sounds well before an imminent crash, giving you some time to react.

I found it useful in one particular case:

I see lots of people overusing the brake and not relying on engine braking.
I've seen cases where they press the brake lightly (so the brake lights light up) then for some reason or another they stomp on the brake (usually see it just before a round-about) Given that the brake lights are already lit, you might be prone to missing that event.

The system in the BMW detects it well before and sounds the alarm if necessary.

[Maxdog]

Originally Posted by ah3

Do you have ACC?

No i don't

[stormlv]

Hmm, I was checking the IIHS site a bit more and found this about the 5 series:

http://www.iihs.org/iihs/ratings/vehicle/v/bmw/5-series

In the 12 mph IIHS test, this vehicle avoided a collision.
In the 25 mph IIHS test, impact speed was reduced by 24 mph.

The difference between the 5 and 3 series seem to be the packages:

3 series:
System details: optional Collision Warning with City Braking function
Package name: optional Driver Assistance Plus

5 series:
System details: optional Collision Warning with braking function
Package name: optional Driver Assistance Plus/ACC Stop & Go + Active Driving Assistant

I'm unsure whether or not the "ACC Stop & Go" or the combination of "ACC+ Active driving assistant" gives the extra oomph in reducing the speed.