[Skyhigh]

To those of you with 440i:

I have only had mine for several months and have not yet really had a good chance to test performance (and didn't want to in the first phase), but something surprised me today:

All settings in default (Comfort mode, etc.), taking over from about 45 km/h.
I pressed the gas-pedal down to kickdown (without going into kickdown). I expected that beyond some stage, the automatic will get my intention to switch to a lower gear and accelerate decently.

Instead, the acceleration was rather mediocre. I am not even sure it dropped gears and if - how many, but it felt like it just tried to accelerate within the current gear from very low RPMs.
I repeated the situation thereafter and reproduced pretty much the same. OK acceleration for an average car, but below my expectations.
Can you confirm this being normal for Comfort mode?

If I use the kickdown, then it aggressively drops the gears and gives a decent kick. But without kickdown... rather close to "Eco Pro" performance with pedal pressed harder.

[lacrimarum]

First of all, it seems to me that gearbox’s decision whether to downshift or not is based not just on the position of the pedal, but also on the way how rapidly you pressed the pedal to current position. If you tap on the gas quickly, it is more likely that there’ll be a downshift. If you are pressing the pedal slowly and gradually, there are more chances that your car will accelerate using currently engaged gear.
My car generally tends to downshift in comfort mode, if the pedal went more that 60-70 percent or so of its way to kickdown, but 40i has much more power and torque, so it is very possible that throttle response and gearbox are programmed in a different way.
And I’d say that throttle responce in comfort mode is quite numb overall.

[Skyhigh]

Valuable post, thanks for that.
That is exactly what I am interested in - the response others (ideally with 440i or 340i) from the throttle in Comfort, without kickdown.

My expectation was that once you pass a delta of say 40-50% to kickdown from the previous position within a short time frame (a clear indicator for an immediate acceleration demand) it will downshift in support of that and provide decent response. In reality however my frustrated thought was more along lines of "Dude... wake up"!?

How do you guys take over when there are time constraints? Kick down? Or prep with manual downshifting?

[bimmer456]

Use sport + mode and shift manually to wake up the beast within otherwise it drives like a Camry with lousy throttle response and floppy suspension. Don't worry about break in period just keep the rpm below 4K and avoid full throttle launches.

[Skyhigh]

Hard to keep them under 4k in Sport mode I have tried of course, including way over 4000 on several occasions for very short periods of time during testing (hope to have done no harm).

The response in Sport mode is of course in a different league, the adaptive suspension is fantastic!
So is your 340i also quite lazy in comfort, e.g. during overtakings?

[Fuller]

What is ecopro and comfort mode? Sounds like settings on a lazyboy recliner.

[rlmesq]

Originally Posted by Fuller

What is ecopro and comfort mode? Sounds like settings on a lazyboy recliner.

They get rid of some of the drone if you're cruising in freeway traffic and don't really want the exhaust valves on MPPSK open. Also reduce steering effort in parking lots and make bumpy roads a little less harsh if you have active suspension.

[Fuller]

Originally Posted by rlmesq

They get rid of some of the drone if you're cruising in freeway traffic and don't really want the exhaust valves on MPPSK open. Also reduce steering effort in parking lots and make bumpy roads a little less harsh if you have active suspension.

Oh I see. That's the good thing about my Prius, it's nice and quiet all the time.

[rlmesq]

Originally Posted by Fuller

Oh I see. That's the good thing about my Prius, it's nice and quiet all the time.

Good. Your neighbors won't hate you. Mine probably do, with that nice startup growl from my car.

[technologic]

I find it downshifts well enough when I gun it in comfort. But of course it's so much quicker to figure out I want to go fast when it's in sport mode.

[COKen]

Don't forget that your car will learn how you normally drive. I'm guessing the different results are because the people who don't have an issue with passing in comfort mode drive more aggressively than those who do.

[Skyhigh]

Learning? Really?
Heard that one before for another car but never seen it formally stated anywhere.

[COKen]

Originally Posted by Skyhigh

Learning? Really?
Heard that one before for another car but never seen it formally stated anywhere.

From the manual ...

On vehicles with an automatic transmission,
the ATC (Adaptive Transmission
Control) uses a number of factors
to calculate the gear which provides the
maximum efficiency. In this process, it
considers your individual driving style
as well as current driving conditions.
ATC recognizes your personal driving
style from the positions and movements
of the accelerator pedal, deceleration
when braking, and lateral acceleration
through curves. Based on different shift
characteristics – from comfort-oriented
to performance-oriented – ATC will
select the appropriate gear.

In order to include driving conditions in
its calculations, ATC registers curves
and both uphill and downhill gradients.
For example, if you maintain speed
through a curve, the transmission does
not shift up. On uphill gradients, it shifts
up only when the engine speed
increases in order to make more efficient
use of power reserves. On downhill
gradients, ATC shifts down when
the speed of the vehicle increases and
the driver must apply the brakes.

[Skyhigh]

Interesting...
I am unable to find this (or similar) text in my manual...
Which chapter is it in?

[HighlandPete]

Originally Posted by Skyhigh

Learning? Really?
Heard that one before for another car but never seen it formally stated anywhere.

'Learning' may give the wrong impression of how the gearbox management works.

'Driver influenced adaptations' is more accurate an understanding, as it is a 'real-time' process, combined along with adaptations for the driving conditions/driving environment.

If we as drivers change our style, the gearbox adaptive management follows very quickly. Plus it restarts driver adaptations every time we start off. We can quickly break current driver adaptations by changing the gearbox program. Simply flick the shifter across to Sport (M/S) for a couple of seconds and back again. That wakes the gearbox up, if we have been driving in a relaxed way for a few miles.

As to the acceleration issue and dropping gears. As already mentioned, how we use the accelerator will influence the gearbox program in use, and appropriate change downs. BMW uses the term "kick-fast", to describe particular accelerator use, part of driver influenced adaptation. The speed we use the pedal, along with the pedal position, measured against the programmed thresholds, to determine which program and gear is most appropriate.

I drive my 535i in the Comfort/Normal gearbox mode/program. To accelerate more briskly, simply flick the shifter to M/S position, and after the overtake, (fast manoeuvre) back the D position and run lower revs again.

If the gearbox is already awake, (typically due to a current mixed driving style), simply use the accelerator pedal to do a similar job, without kick-down. Even a slight jab on the pedal should trigger a down change, ready for a bit more progressive action.

I agree the 40i engines may be programmed slightly different to the 35i engines, but the accelerator/gearbox principles are the same.

[Skyhigh]

Thank you for your post and explanation.
This is my first automatic car and quite honestly I am lacking control and predictability. I still find our second car (Audi A3) with less than half the engine power but manual transmission to be significantly more predictable when it comes to throttle response and acceleration. And sometimes (when the (milli)seconds are limited) this matters much more than 1000 PS. Of course I realize that to a big extent this is due to my lack of experience with the car and automatics in general, which is why I am curious about how you guys go around in everyday situations.

One of my colleague is driving a 650i. One of his first advises when I got the 4-Series was that I should use manual shifting, as the automatic is not to be trusted when instant acceleration is required (in Comfort mode that is)...

[HighlandPete]

Originally Posted by lacrimarum

My car generally tends to downshift in comfort mode, if the pedal went more that 60-70 percent or so of its way to kickdown, but 40i has much more power and torque, so it is very possible that throttle response and gearbox are programmed in a different way.

I agree the 40i is likely to have much tighter control of the gearbox and change points, particularly in Comfort mode. Will be programmed to ride the torque. Very much as the big diesels are set up, to stop hunting gears with small accelerator movements.

I remember when I was running my 540i with the 5-speed ZF auto-box, my brother-in-law was running a 2.2i Z3 with essentially the same ZF box. Totally different gearbox programming and function. The slightest twitch of the accelerator in the Z3 and the gearbox went hunting for lower gears. Whereas the 540i would hold a gear with much greater torque loadings. The loud pedal in the 540i needed a bit more action to instigate down changes.

[HighlandPete]

Originally Posted by Skyhigh

Thank you for your post and explanation.
This is my first automatic car and quite honestly I am lacking control and predictability. I still find our second car (Audi A3) with less than half the engine power but manual transmission to be significantly more predictable when it comes to throttle response and acceleration. And sometimes (when the (milli)seconds are limited) this matters much more than 1000 PS. Of course I realize that to a big extent this is due to my lack of experience with the car and automatics in general, which is why I am curious about how you guys go around in everyday situations.

One of my colleague is driving a 650i. One of his first advises when I got the 4-Series was that I should use manual shifting, as the automatic is not to be trusted when instant acceleration is required (in Comfort mode that is)...

My advice in discussions like this, is to experiment. Try the shifter trick, flick to M/S for a more instant response... then back to D. Manual shifting does give a particular type of control, but auto changes are much more useable and controllable than some drivers seem to master.

I've been driving BMW autos from the 5-speed ZF. Experience of the 5, 6 & 8-speed, with years of driving each example.

The ZF 8-speed is probably the best slush auto-box out there, learn to exploit it and it does reward the driver.

[Billfitz]

Originally Posted by technologic

I find it downshifts well enough when I gun it in comfort. But of course it's so much quicker to figure out I want to go fast when it's in sport mode.

+1. In comfort you're pretty much telling the car you're not in a particular hurry. In sport it expects to be pushed harder. Also, when you go to sport it runs at a lower gear and higher RPM, getting the turbos up to speed and putting the engine into the higher torque curve, requiring less time to giddy-up. I don't bother to manually shift, but when I anticipate wanting to pass at a more than leisurely rate I pop it into sport and it delivers.

[simonelwell]

Prev 335i
current 440i

I will test tomorrow but I think I get kickdown in comfort. Personally I use comfort only when traffic prevents me from using the full rev range and power of the car. As soon as possible I shift to sport+and push the gearbox into sport too...

[Skyhigh]

Not at all worried about fuel consumption then?
I can't say I am (would have made the wrong car choice otherwise), but looking at those big double-digits makes me hesitant whether I would like to drive in Sport for no reason, meaning in normal, daily A to B traffic.

[Billfitz]

Yeah, everyday highway driving in sport won't get you there any quicker but it will take a lot more gas to get there. It's like cruising at 70 in seventh gear instead of eighth, because you are.