Not to make this a 6 vs 8 cylinder thing...but since I've only driven the V8 BMWs that have ATC...if you need to quickly pass someone like in the scenario you mentioned...you can actually achieve the same thing by just mashing the accelerator pedal.

ATC has an adaptive sport mode (kick-down) that do a single gear drop down at speed...or even a two gear drop down if the accelerator pedal is smashed to the floor hard enough and you achieve basically the same reaction from the tranny & engine...all without having to mess around with the gear shift lever. See KICK-FAST FEATURE info below. :)

The accelerator pedal is monitored and a quick sustained movement will be interpreted as the driver being aggressive...so the driver influence is picked up by ATC and sport mode is initiated...which is how the "adaptive" nature works. When the ignition is switched off...the driver influenced adaptations are NOT remember...because they are not stored in the TCM (tranny control module)...thus upon the next start-up and driver...the influences are renewed.

No. You feel more engine braking because the shifting program has been changed to hold a lower gear longer.

The DME changes to engine timing, and the DDE changes to fuel injection, last only milliseconds. They occur during the shift, not before or after it. During the shift, engine power is automatically reduced by the DDE and DME to make the shift smoother (in all modes). It makes it feel smoother, reduces the load on the clutches, makes the transmission last longer, and keeps the fluid cleaner, all by reducing slipping of the clutch plates.

Again, cool info on the nuances that make a BMW a BMW. :)

I've pushed into the kick down feature while in D and found it pretty jerky and rough. So I don't do it very often. If I need to drive like a bat outta hell, I put it in Sport mode and the shifts are much smoother.



This is fantastic info! Thanks for all the replies and tying the technical reasons to the feeling.


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You suppose right. It is from Dinan. Price is $299 for transmission software. Unless there has been a change Dinan products must be installed by a Dinan authorized shop. It should not take more than half an hour.

Whether it is too costly or a value depends on what one is trying to achieve. Software raises shift points in sport and economy modes, firmer and quicker shifts, full control in manual mode, automatically downshifts to third when stopping in manual mode and will shift automatically in manual mode if kick down switch is activated. I am very pleased with the benefits and think it is a great value because I like all that stuff.

BMW must be copying Dinan because the E70 in manual mode does the following as standard:

automatically downshifts to second when stopping in manual mode and will shift automatically in manual mode if kick down switch is activated.

For me the manual mode is fun for those times when I want to control exactly what the car does but those are few and far between - so I definitely do not miss a manual transmission. The auto changedown to an appropriate gear when slowing down (it will choose depending on how slow you have reduced your speed to) in manual mode is great because that's the part of genuine manual shifting that I really hate.

I have also "sensed" a change in transmission behavior when towing as well. I know the vehicle is aware of the trailer because of the wiring harness load, so I am thinking sport mode or some degree of it, is automatically engaged when I've got the trailer out back. Any thoughts?

2002 X5 3.0 252,000 miles
2004 325i 113,000 miles

Perhaps it is locking up the torque converter faster? That would keep trans fluid temps down I think.

Yeah, I was a bit (a bit?) pejorative there...sry.

Dinan engineers fine products, no doubt.

I don't have a problem with the current 'learned' shift program in my X5 in normal mode. I like sport when I want to do an italian tuneup, with the exception of the slowing down to a stop smoothly issue. If the Dinan software solves that issue, then it would be worth it to me. If it doesn't, then I'm good with what I have. Sometimes not knowing what's available is better for me. Definitely better for my wallet. :D

:wow:Connecting a trailer has never been reported as a modifier of the transmission shifting program, so no, I don't think it changes to a tow mode.

What the transmission does do is consider vehicle speed, throttle position, and so on when selecting a gear, so it is entirely to be expected that adding drag (eg a trailer) and thus requiring more throttle at a given speed will change shifting characteristics.