[walmark]

I never use the kickdown feature (the little "click" at the bottom of the accelerator pedal) but today I tried it out. It is completely pointless!

When you hit it, the transmission will downshift TOO LOW (~6k RPM ?!?), so you have very little RPM left, and after less then a second it has to upshift anyway. In comparison, when I press the accelerator all the way without the click, the transmission downshifts to a REASONABLE gear (~4k RPM), allowing for efficient and smooth acceleration.

What is the point of the kickdown button? To jerk the car/passengers while making a lot of noise? With 0.5 second of acceleration before upshift you're not going far anyway. Unless I'm not doing it right...

(Note: please, no responses containing only the word "manual" )

[AWil335i]

Do the Kickdown Blocker DIY.... you won't regret it.

[Dark_Knight_335]

Yea, not sure what it really does either.

[TokyoCarGuy]

I use it for downshifting when I want to slow down sometimes. It will not up-shift if you keep your foot off the gas and hence engage engine braking. Since it will remain in auto mode it will engage proper gear on its own once you decide to accelerate again, as opposed to paddle shifters (or manual mode) which will hold the gear for far too long.

[NjPrince]

Idk man...last time I used it my car went airborne

[MGT81]

Manual. Manual ftw. I love how precise the throttle responsiveness is with the stick.

[TokyoCarGuy]

Originally Posted by MGT81

Manual. Manual ftw. I love how precise the throttle responsiveness is with the stick.

believe it or not, but they never sold manual 335i in Japan. Moreover after having to replace your left leg after hours in Tokyo traffic with tons of up-hill starts, you'd be wishing for an auto.

[AzureHaze]

It is pointless.

[mashimarho]

I've never found out what it did. I never used it to blip the throttle in my 6mt for downshifts. Maybe, I'll try it next time.

Does anyone have a precise answer as to what it does?

[Dark_Knight_335]

After several posts on this thread, I can almost liken it to that "door close" button on the elevator that usually does absolutely nothing.

[els_86]

I'm with ya, I don't get it at all. I think it is there to maximize the power output when you floor it though, right? I mean if you are in auto or sport mode, it keeps the rpm's in their maximum power range?

I hate it though, but I think this is why it is there...

[MalcolmV8]

OK now I feel like an idiot, never even heard of this kick down button. Do all the cars have it? I need to go look at mine now

[Delta0311]

Originally Posted by MalcolmV8

OK now I feel like an idiot, never even heard of this kick down button. Do all the cars have it? I need to go look at mine now

Push gas pedal all the way down till you feel it "kick down". Pedal to the floor man.

[sy2767]

Originally Posted by Delta0311

Push gas pedal all the way down till you feel it "kick down". Pedal to the floor man.

With the engine off slowly push down on the pedal until you feel some resistance, at that point push a bit harder and you will feel the kickdown button engage. Came in handy with my 325 but in my 335 it just over revs the engine to the point i'm not making any more power and it drops off.

[MalcolmV8]

Oh shoot I've driven pedal to the floor quite a bit. Never noticed it. Maybe I didn't push down hard enough. OK as soon as the car is running again I'll have to play around and check that out.

[PhaseP]

Originally Posted by sy2767

Came in handy with my 325 but in my 335 it just over revs the engine to the point i'm not making any more power and it drops off.

In N/A versions of these engines, the torque curve is still going good at high rpms, so for max accelaration staying at low gear until redline is needed.

The turbo 335's torque curve starts to droop earlier in the very high rpm range, the loss from torque curve actually may become more than the torque loss from going high one gear up with those engines at close to redline. I think this is what people are experiencing. Maybe the kickdown feature is not customized for turbo vs N/A engines in factory, always putting it low gear as low as possible. Makes sense with N/A engines, not always sensible with turbo engines that have high torque early on the curve that droops earlier also at high rpms.

I have manual so I am just guessing, not first hand experience.

[DUI Elite]

I avoid using it. I push until the point just before the kickdown button. I hate it for the same reasons described here.

I usually drive in manual mode anyway, so if I really need the acceleration, I'll downshift appropriately lol. The car doesn't always calculate well.

Time wasted shifting to TOO low of a gear = slow, because like you said, it just has to shift back up within a half second because its at the top of the rpm band.

From my experience, it tries to drop 2 gears when downshifting one would get the job done perfectly.

[SuaveSpoolin]

Originally Posted by Njprince0226

Idk man...last time I used it my car went airborne

[iturbo_bmw]

pretty sure its just there for emergency situation where a "normal" driver might just need to go full power

[GMe90]

Originally Posted by DUI Elite

I avoid using it. I push until the point just before the kickdown button. I hate it for the same reasons described here.

I usually drive in manual mode anyway, so if I really need the acceleration, I'll downshift appropriately lol. The car doesn't always calculate well.

Time wasted shifting to TOO low of a gear = slow, because like you said, it just has to shift back up within a half second because its at the top of the rpm band.

From my experience, it tries to drop 2 gears when downshifting one would get the job done perfectly.

+1. Manual mode is awesome!

[m@rco]

The kick-down resistance/button is there to avoid that your car would shift 'aggressively' to the lowest gear possible for maximum acceleration.

In most instances when you (or manual drivers) hit full throttle, you prefer to accelerate as fast as possible without excessive gear changes and extreme revs.

For example, you see the traffic light turn amber and you just want to accelerate quickly. If you're doing 30mph at that moment, it is not so comfortable to suddenly go back to 1st gear. By not pressing through the resistance, your car will either stay in 2nd gear or move from 3rd or 4th back to 2nd.

Another example: If you're merging onto the interstate. Let assume, you're driving 'easy' 50mph behind a couple of slower cars. Your engine will be in 4th or 5th gear. Once you see a space, and you want to accelerate quickly, you want the engine to shift down 3rd gear. By pressing full throttle without pushing through the kick-down, your engine will probably only shift as low as to 3rd gear. Even though for maximum acceleration, it would have to go back to 2nd. But that is very uncomfortable.

If you didn't have the kick-down resistance under your foot, you wouldn't exactly know how deep to press the accelerator without shifting down too far.

Now, imagine that you're climbing a steep, 2-lane curvy road in the mountains. And you're doing 30mph behind a truck. Depending on the slope, you're engine will probably be in 3rd or 4th gear so long you are cruising/waiting behind the truck. Once you have found a space to accelerate, and need full power, you floor the pedal (through the resistance) to make sure that it goes to 1st gear to get the maximum acceleration so as to pass as quickly as possible. In that instance, you don't want it to stay in 2nd for comfort... You need all the horses in action, and, your engine may shift to a gear that produces revs around 5,000rpm. Your engine delivers more horsepower or kiloWatt (= Joule per second = Energy per Second) at higher rpms. Therefore it is 'faster' to accelerate from 5,000 to 6,500 rpm than from 4,000 to 5,000rpm.

Hope this clarified.

[alexwhittemore]

I use kickdown all the time in my 328. Usually I'm not in sport mode (wildly better economy around town), so when I want to make a pass or otherwise ACTUALLY GO, I hit the kickdown and then once I've dropped a gear, manage throttle from there. It's much less useful in sport mode where the throttle lag isn't nearly as pronounced. By the time you're at WOT to hit the switch, the car's already gotten the message you want to go somewhere, and by the time the gear change is executed you've only got 1-200 RPM left before the upshift, so it's sort of more trouble than it's worth.