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-   -   Sluggish feel when in reverse (http://www.bimmerfest.com/forums/showthread.php?t=416307)

labart 12-01-2009 06:25 PM

Sluggish feel when in reverse
 
Can someone enlighten a first time BMW owner about the sluggish feeling when driving in reverse as compared to other cars? Especially noticed the first time of the day when cold. Any comments appreciated.

enamoured 12-01-2009 08:10 PM

All cars I have owned had a little "heavy" feeling and somewhat rough gear shifts when cold. That's because it takes sometime for components to reach their nominal operating temperature and for oil to circulate through all moving parts. BMWs are no exception.

X3-terrestrial 12-02-2009 01:06 PM

Quote:

Originally Posted by labart (Post 4730142)
Can someone enlighten a first time BMW owner about the sluggish feeling when driving in reverse as compared to other cars? Especially noticed the first time of the day when cold. Any comments appreciated.

Here's my take on this, but don't quote me since is my own conclusion. These cars are DBW (Drive by wire) technology, meaning that there's no actual cable between the accelerator pedal and the throttle body. With that said is possible for the ECU (via programming) to control how the inputs are received by the TB's butterfly, thus adjusting sensitivity. An example of this is the SPORT mode on e46 M3's that gives more sensitivity to the gas pedal via programming, making it feel more responsive.
My guess is that in REVERSE, the program actually is the oposite, (less sensitive) since when you are backing up you don't need a fast throttle response.

Engine/tranaxle temperatures also play a roll on this as said above.


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