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My 2020 MDX SH-AWD has 498 miles. The paddle shift technology was one of the features that drove my decision to buy the MDX. I have driven a Grand Cherokee with this feature for years so I'm familiar with the operation and use it often. In the MDX upshifting is normal, but downshifting is puzzling to me. I use the downshift paddle to allow the trans to slow the vehicle in a downhill situation instead of riding the brakes. Each downshift selection responds with an RPM increase. My reason for posting is to learn from other owners if this 'reving' is normal operation for this feature? Logically, it makes no sense since the purpose of downshifting in a downhill situation is to slow, not increase, the vehicle speed. So instead of saving my brakes I need to brake harder to offset the RPM increase! I've tested this shifting in all Dynamic modes (Comfort, Normal, Sport) and the operation (reving) is the same. Has anyone else observed this?
 

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I don't have a 9AT MDX; but, had 4-5 3rd Gen loaners. The weird characteristic of increasing speed when downshifting always puzzled me also. Wasn't as fun having to downshift 3-5 gears to get the same effect in the 9AT compared to 1-2 gears in my 6AT/5AT in my 11 MDX or 08 RDX. I just stopped playing with the paddles when I had the 3.5L MDX loaners. That was one of the reasons I decided on the hybrid with the 7DCT. The combo of 3 electric motors TQ, regen braking, tq vectoring on/off throttle, and the 7DCT always seems to be in the right gear has eliminated the need to use the paddles for inclines or slowing down for curves.
 

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Discussion Starter #3
So you're saying that the revving on paddle downshift is normal operation? Thinking it might be ok in the Sport setting, but not in Normal or Comfort. If this is how the car is designed I guess I get to live with it, but will not like it as much as the way Jeep does it. So much for saving my brake pads :cool:
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When you downshift your RPMS will increase as you’re going to a smaller gear at the same speed of the larger gear.

This is how all manual transmissions work; the benefit of a manual shift if you can get a higher RPM before a shift to the next gear. While the MDX will not allow you to make a damaging up or downshift with the paddles in a real manual transmission especially a motorcycle, if you downshift at the wrong speed you’re going to wipe out.

The behavior you are describing is normal to me.
 

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Discussion Starter #5
Thanks for the reply. Actually it may be normal for some vehicles including Acura, but not Chrysler. My Jeep paddle downshifting does not come with increased rpm, in fact I can do a downhill turn without touching the brake. Yes, the Jeep will also increase the rpm at each downshift, but it happens after the shift and not before. The revving before each new gear forces me to brake just to help slow it down. You call it a 'benefit', but to me it's taking away from the intent of downshifting, ie. to save on my brakes. Wish I had paid more attention to this during the test drive.
 

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What do you mean before the downshift? I don’t even see how that’s possible unless the computer decided it needed to shift before driver input?

I can engine brake with my MDX and the paddles. The RPM’s only jumps after my downshift.

Maybe I am not following what you are experiencing?
 

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So you're saying that the revving on paddle downshift is normal operation? Thinking it might be ok in the Sport setting, but not in Normal or Comfort. If this is how the car is designed I guess I get to live with it, but will not like it as much as the way Jeep does it. So much for saving my brake pads :cool:
View attachment 115299 View attachment 115299
Bennfun, nice looking MDX! Here’s mine:
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Discussion Starter #8
What do you mean before the downshift? I don’t even see how that’s possible unless the computer decided it needed to shift before driver input?

I can engine brake with my MDX and the paddles. The RPM’s only jumps after my downshift.

Maybe I am not following what you are experiencing?
Your point is taken, I'm not being clear. Thinking more about comparing the two vehicles with paddle shift. Yes, both will always have increased rpm when downshifting to lower gear. However, the Jeep does not accelerate, thus the shift down gives all the advantage of braking with the engine/trans. In the same situation the Acura actually accelerates a little with each downshift which then offsets the goal of engine/trans braking. We have a lot of hills in TN so I downshift for downhill turns onto our street. In the Jeep I hardly need to brake, but with the Acura I'm forced to brake to offset the acceleration at each shift point. I drove a Mercedes with paddles and it works the same way as the Jeep. It just seems strange to me that the trans would be programmed this way - don't see the reason. It's a hard concept to explain in writing and of course best observed in actual driving. Hope that's more clear. Gotta love the MDX in red (y)
 

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I use the downshift paddle to allow the trans to slow the vehicle in a downhill situation instead of riding the brakes. Each downshift selection responds with an RPM increase.
Of course, it does - you are going to a lower gear at the same speed, meaning the engine RPM increase. Just like the RPM will decrease when you shift up. That's the purpose of a transmission.

I'm not sure what you are asking, as that's the basis of how a non CVT transmission works.

So instead of saving my brakes I need to brake harder to offset the RPM increase!
Are you saying your car speeds up when you are shifting to a lower gear and lift off the accelerator? That makes no sense.
 

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Are you saying your car speeds up when you are shifting to a lower gear and lift off the accelerator? That makes no sense.
That is what I felt when I was playing with the paddles on the 9AT 16 MDX loaners I had in the past. I like to hit the curves by downshifting to slow down with engine braking and use the gas pedal to engage sh-awd through out the curve. The sensation felt like the MDX was accelerating with downshifts instead of engine braking before I entered a curve.
 

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slow internet, posted same response twice........
 

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Discussion Starter #12
Of course, it does - you are going to a lower gear at the same speed, meaning the engine RPM increase. Just like the RPM will decrease when you shift up. That's the purpose of a transmission.

I'm not sure what you are asking, as that's the basis of how a non CVT transmission works.

Are you saying your car speeds up when you are shifting to a lower gear and lift off the accelerator? That makes no sense.
Yes, that's what I'm saying. And thus my post - it makes no sense. Yet folks with the same car/trans say this is how it's supposed to be. Well, it may be normal operation for the MDX, but having driven other paddle equipped cars - they don't do this. I note that mrgold35 has observed the same thing.
 

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I haven’t drove a 9speed but I know for my 2015 - 6speed it engine brakes when I downshift from the paddles, no acceleration.

At my next drive I’ll pay more attention to see if that happens but I think I would have noticed that.

maybe the 9 speeds acts differently but it still doesn’t make sense to me unless the computer is trying to compensate for the increased RPMs by giving it gas to bring the RPM’s down but that wouldn’t be a drivers expected result.

If that’s the case - I agree with you. That’s lame and why bother have paddle shifters if you really can’t control the drive.
 

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That is what I felt when I was playing with the paddles on the 9AT 16 MDX loaners I had in the past. I like to hit the curves by downshifting to slow down with engine braking and use the gas pedal to engage sh-awd through out the curve. The sensation felt like the MDX was accelerating with downshifts instead of engine braking before I entered a curve.
I downshift when going down a steep grade when towing our Airstream to save the brakes, but also when towing in 5th gear to increase the rpm to obtain more torque when traveling between 68-72 mph. Also going into a curve the downshift to increase the rpm’s seems to add better control. Better torque vectoring?


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I downshift when going down a steep grade when towing our Airstream to save the brakes, but also when towing in 5th gear to increase the rpm to obtain more torque when traveling between 68-72 mph. Also going into a curve the downshift to increase the rpm’s seems to add better control. Better torque vectoring?


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The sh-awd system only works with engine power. Most of time when entering a curve you would brake to bleed off some speed, coast/ride the brakes until around 1/2 into the curve, and then use the accelerator to try and match the posted mph gradually before hitting the straight.

I don't do this all the time; but, I downshift to engine brake slow down before the curve (I'm entering the curve at 5-15 mpg above the posted curve speed), slowly apply the gas pedal to engage sh-awd, I begine to apply more gas to get the rear to tq vector to help rotate, and I'm usually at or above the posted speed limit before getting out of the curve. This really helps with the 270 degree hwy on ramp has a posted speed of 25 mph; but, it enters onto a 65 mph hwy (with trucks/cars driving 60-80 mph). Easier for me to match the hwy speeds when exiting at 50-60 mph compared to 25-35 mph.

I don't have to use the paddles in my hybrids because they tq vector on or off engine power.
 
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