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Old 12-02-2009, 01:06 PM
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X3-terrestrial X3-terrestrial is offline
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Location: N.Miss - Memphis,TN Area
 
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Mein Auto: '05 X3, '95 M3, '89 MkI
Quote:
Originally Posted by labart View Post
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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