Delay in accelerating at higher speeds

[MichaelInChicago]

Over the last few months, I have noticed that when traveling at speeds higher than 20 mph in normal mode, there is a delay in the response when I press down on the accelerator pedal, to the point that I have to press pretty far down to accelerate, and in some cases, this could be dangerous when changing lanes, for example.

When I have the car in sport mode, however, the delay is reduced quite a bit. In every other way, this car performs remarkably

Does anyone else have this issue and, if so, is it normal or should I have BMW take a look at it?

I have a 2015 650xi GC.

Thanks

[thedza]

there's a lag in standard mode for sure. I'm typically fine with it going most places around the city where I'm not driving fast or switching lanes/overtaking (and sport can be excessive/a bit jerky), but anytime I know I'll be doing any highway driving I switch to sport.

[Giggs11]

I always drive in sport period , bad on gas but ooo well

[murph914]

A lot of guys have complained about "throttle delay". Many blame the throttle pedal's delayed response to some sort of evil vodoo introduced by BMW engineers to try and make the drivetrain be smoother and last longer.

Many people including myself plug a pedalbox inline just after the accelerator pedal to change the throttle mapping. It makes higher throttle come on quicker and eliminates a lot of that "lag".

People for it say it eliminates throttle lag and makes the car feel like it has more power. People against it say it just makes the throttle into an on/off switch and removes the dynamics that BMW spent so much time and money perfecting.

For $300 and about 10 minutes to install it, it's worth it to play around. I wouldn't say it's perfect, but it is fun to add another thing to be able to change and make the car a little sportier at times.

[Opie55]

You are sensing the delay it takes for the engine to build revs then to shift the tranny down. When you are going a steady 30 mph, the engine is loping along barely awake and the tranny is in a higher gear. If you drive in sport the car is sort of pre-prepped for you to hit the gas. Or if you hit the paddle shifter to go down one gear before you accelerate it will have the same effect. It's not really just a turbo lag thing either. My last car was a non-turbo MB with a big V8 and what you describe was the most annoying thing about it.

[MichaelInChicago]

Now that you mention it, it does feel more like a transmission issue than an engine lag issue.

I can press on the pedal and it just feels like there is nothing there for a second or two until the transmission downshifts and the car then accelerates properly.

Is it normal for the transmission to have this second to two second delay when downshifting?

[Opie55]

Originally Posted by MichaelInChicago

Now that you mention it, it does feel more like a transmission issue than an engine lag issue.

I can press on the pedal and it just feels like there is nothing there for a second or two until the transmission downshifts and the car then accelerates properly.

Is it normal for the transmission to have this second to two second delay when downshifting?

With the caveat that I have not driven your car and there is always the possibility that yours is different, yeah, it's normal to have a rather large dead spot when accelerating quickly from those mid-range speeds.