Please explain the kickdown switch to me

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2022 CX-5 S Select
2024 CX-5 Prem Plus
1984 RX-7 GSL-SE (long gone)
Title says it all. I don't understand the point of this feature.

If I stomp on the accelerator won't the transmission downshift normally anyway? At least that's been my experience in every other AT car I've ever owned.

Or why not just switch over to manual mode and downshift? Or use the paddle shifter which my wife's 24 CX-5 has?

I don't like having to race the engine just to drop down a gear. There are other ways to do this, no?

What am I missing?
 
To the best of my knowledge there is no kickdown switch on the CX-5's. That detent that you feel at WOT is just there as tactile feedback to tell you that you are in fact at WOT and to quote a line from the song Hot Rod Lincoln:
"My foot was glued like lead to the floor
That's all there is and there ain't no more"

Flooring the CX-5 will generally force a downshift but that is only because the ECM is trying to match yoor request for maximum acceleration.

In the past before everything was electronic, there was mechanical linkage between the throttle of the carburator and the transmission that provided a kick-down to a lower gear at WOT.
 
I've owned three Mazdas with the SkyActiv drivetrain. 2013 and 2023 CX-5s and a 2018 3. I have never sensed anything like a mechanical kickdown switch in any of them despite reading years ago that Mazda began using them across the board in the mid-teens.
 
Well, something clicks when you floor it. I don't like to do it, but I've tried it on both my wife's 2024 and my daughter's 2022 and there's a click. Whether that forces a downshift, or it just downshifts like every other auto when you floor it because it thinks you need more power, I don't know.

Only thing I can think of is maybe by flooring it quickly to hit the switch it drops the gear a little quicker?
 
Remembering my Mazda6 with the 2.5T setup, when playing in manual mode, clicking this switch used to force the car to downshift if possible to get max acceleration (exactly like @cadcamjim mentioned). Not sure if that's the case in the CX5 but something someone could verify, perhaps.
If you had the traction control off, it wouldn't downshift when you engaged the kickdown switch.
 
Remembering my Mazda6 with the 2.5T setup, when playing in manual mode, clicking this switch used to force the car to downshift if possible to get max acceleration (exactly like @cadcamjim mentioned). Not sure if that's the case in the CX5 but something someone could verify, perhaps.
If you had the traction control off, it wouldn't downshift when you engaged the kickdown switch.
If you're in manual mode why would you use the kickdown switch instead of the shifter?

I guess my main confusion is why Mazda would want you to rev the engine potentially to redline just to drop down a gear, when there are two or three other ways to do it that seem much easier on the engine.
 
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I guess my main confusion is why Mazda would want you to rev the engine potentially to redline just to drop down a gear, when there are two or three other ways to do it that seem much easier on the engine.
The engine is not going to redline before downshifting for two reasons. 1) slamming the accelerator pedal in-gear during cruising speeds without a shift will just lug the engine. When in-gear, engine RPM is mechanically locked to vehicle speed. 2) if the engine is at a high RPM, it is out of the allowable range for the lower gear and will only shift up, not down.

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Also from the Owner's Manual:

Kickdown

When the accelerator pedal is depressed fully while driving, the gear shifts down.

However, the gears do not kickdown while the TCS is turned off or the Off-Road Traction Assist is operating.
 
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Go full throttle without pressing the kickdown switch, and the transmission usually won't downshift into the lowest possible gear. The computer deems that it's not the "most urgent" request for WOT. It will typically bring the engine to around 4000rpm before accelerating, or might not even downshift at all, depending on the scenario.

Now, go full throttle while pressing the kickdown switch, and the transmission deems this as an urgent request, meaning it will put you into the lowest possible gear allowable at your current speed. I have seen the transmission downshift so aggressively, it began pulling from around 5700rpm!

Picture this scenario. You're cruising at around 80km/h at 1500rpm in 6th gear. You go WOT to pass, without pressing the K/D switch. the transmission will likely downshift to 3rd gear. Now, in that same scenario, with the K/D switch pressed, it will likely downshift to second gear instead.

For example. A real scenario that happened to me once: I went WOT to pass. Oncoming traffic came around the bend. I had little space left. I clicked the K/D switch and it automatically dropped one more gear, giving me just enough acceleration to merge in time. Using it is very hard on the transmission and hardly ever necessary. Use sparingly.


The only other thing i've noticed is where the transmission actually shifts. Go WOT in say, second gear. Urgent, but not the most urgent request. The transmission is programmed to shift as high as reasonably possible in a scenario that it assumes is, urgent, but not K/D Switch urgent. It seems to shift somewhere between 5500-6000rpm on average, depending on conditions.

Now, try WOT with the K/D, and it will go all the way up to redline, without any exceptions that i've seen, though I hardly experiment with anything near that RPM.


I have not noticed any difference in behavior between holding the switch, vs. simply clicking it. Appears it's designed to be clicked briefly.

Messing around with this switch while hooked up to Mazda edit, I noticed that you get more throttle opening, as the pedal is obviously closer to the floor, but during actual WOT testing, the ECU won't actually allow the additional throttle position. Let's say the ECU determined that 86% throttle position at WOT is the most it can give you without impeding on drivetrain safety, there's not a thing you can do to get that figure any higher. Not that you would want to! I've never seen the throttle open up any higher than 86% while tuning.


So, in short:

WOT with the K/D switch is essentially asking your drivetrain for everything it's got.

pressing the switch will probably speed up the upshifts somewhat, maybe alter torque converter lockup slightly, but nothing noticeable to me in that regard. The downshift speed, aggressiveness, and the redline shift are the main two things i've noticed.
 
Only thing I can relate it to is driving a vehicle that had a 4 barrel carb. When you floored it you knew it. My first car (84 Camaro Z) that I later swapped in a L98 from a Corvette and kept the 4 barrel it sounded like it was sucking in trees when opened up. I don't like the kick down or spot where you have to apply more pressure on the gas pedal to go faster. I just want it all with no delay :)
 
Only thing I can relate it to is driving a vehicle that had a 4 barrel carb. When you floored it you knew it. My first car (84 Camaro Z) that I later swapped in a L98 from a Corvette and kept the 4 barrel it sounded like it was sucking in trees when opened up. I don't like the kick down or spot where you have to apply more pressure on the gas pedal to go faster. I just want it all with no delay :)

it's entirely logical. you have the option to choose based on how hard you press the pedal at WOT.
 
My car has a manual transmission and also has the kick down switch.
According to my dealer, this kick down switch ensures that the speed limiter (when used) will be overruled when, for example, you need extra speed while overtaking another car.
Because I have never used the speed limiter in my car I have not tested this behavior.

All new cars sold in the European Union from 7 July 2024 must have Intelligent Speed Assistance (ISA) speed limiter tech fitted by law, but that is a more "intelligent" speed limiter than the one in my car. The speed limiter in my car just limits the speed to a manual set maximum speed.
I belief that the system in my car was also mandatory in Europe, but in my opinion completely redundant if the car is equipped with cruise control.
 
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WOT should be the max (to the floor) not limited to a certain specific point in pedal travel. I have 2 sports cars and WOT is when the pedal is to the floor not a specific point (say 75% of pedal travel)
 
Only thing I can relate it to is driving a vehicle that had a 4 barrel carb. When you floored it you knew it. My first car (84 Camaro Z) that I later swapped in a L98 from a Corvette and kept the 4 barrel it sounded like it was sucking in trees when opened up. I don't like the kick down or spot where you have to apply more pressure on the gas pedal to go faster. I just want it all with no delay :)

These are pretty much my thoughts as well - give me what you got, don't try to outhink me. But I get that's not how cars work anymore.

If I'm understanding the explanations correctly, the kickdown switch basically tells the car "I need power and I really, really mean it this time!"? I can see that.

I may play with it a little more but I still don't like the thought of racing the engine for this. I was always taught that was bad.
 
If you need to drop down a gear but don't really need to go WOT, just use the paddle or shift lever.
 
If you need to drop down a gear but don't really need to go WOT, just use the paddle or shift lever.
Right, that's exactly why I don't really understand the point of the kickdown switch.
 

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