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Discussion Starter #1 (Edited)
Here is a video with a fascinating discussion of the Niro with a KIA American Executive. They discuss the Niro journey from a concept to design to manufacturing to selling it. The discussion is in the first 30 minutes of the video in the interview with the Kia Executive. Discussions begins about 3 minutes into the video

 

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Thanks for posting, that was a cool interview. I laughed out loud though when they claimed how smooth the launches were with the DCT. That's been a common complaint I've read about on the FB groups and by reviewers on how launches can sometimes lurch or stall. That's my only pet peeve with the car. I'm used to driving e-CVT hybrids and single reduction gear EVs. They are all so much smoother than the DCT in the Niro. I know they were going to sportiness and wanted to differentiate themselves from the Prius, but there's a reason there's millions of Priuses out on the road. Sometimes a little imitation is healthy.
 

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Really enjoyed it. I can't imagine complaints over the launch other than a high performance start. Those can be a little rough. The DCT trait that I really like is the fact that it is always directly connected, no slush pump. That's why the launch is always electric. The PHEV does have a bit more powerful electric so a moderate to heavy launch might be smoother than the HEV.

KIA seems in a good position. The new Prius IMHO, is no less than butt ugly and the CVT just feels inefficient. I think the body shape hit the mark perfectly between efficency and utility. I just wish they made it in the US plant.
 

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Since the electric motor is going through the DCT on the PHEV (and likely the HEV as well), I can understand where it doesn't work as well as a CVT. My only complaint about the PHEV drivetrain is running out of EV power when climbing a hill while also attempting to accelerate. One example would be an uphill freeway on ramp, while another is just climbing the hill I live on from a dead stop at the bottom (3 way stop). I often notice the DCT changing gears attempting to keep the power flowing, but it's often shifting later than it should. A CVT would most likely be able to match the available motor power to the demand and stay out of the ICE more often.

My experience with a CVT was the Subaru Outback I traded for my Niro. Since it had the 3.0 six, not the 4 cylinder, the CVT was silky smooth and rarely revved the engine excessively. When I test drove the Honda Clarity, that CVT was particularly annoying if the ICE had to start.
 

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It doesn't matter which gear you are in or how fast you are going, the motor is capable of putting out max power. None extra from downshifting. The PHEV has a small motor relative to most EVs, and is just not capable of maintain speeds under some demands without backup.
 

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It doesn't matter which gear you are in or how fast you are going, the motor is capable of putting out max power. None extra from downshifting. The PHEV has a small motor relative to most EVs, and is just not capable of maintain speeds under some demands without backup.
True, but a lower gear in the transmission can increase torque at the wheels, which would improve acceleration. And I have absolutely felt it downshift under electric power.
 

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True, but a lower gear in the transmission can increase torque at the wheels, which would improve acceleration. And I have absolutely felt it downshift under electric power.
Yes, for max acceleration one wants max HP. HP is torque x rpm. Most motors, including the niros, have a flat torque curve so one wants max rpm for max HP. This means lower gearing than the niro typically selects. Would be nice to have an EV only sport mode.

The other rpm limiter is max Kwatts from the battery. The HEV and PHEV motor is the same, same torque rating. The difference is the PHEV has a larger, higher power rated battery which can drive the motor to higher RPMs thus more HP.
 

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I'm confused, probably because "motor" seems to be used interspersed with "ICE".

Electric motors typically put out max torque at all reasonable RPM's, if called for. From what I understand the HEV motor puts out 43 HP and the PHEV 60 Hp. If it weren't for the ICE, a transmission would likely be unnecessary.

The ICE puts out 0 torque at 0 RPM so it needs a transmission of some sort. If the trannie is direct drive, it can't even run with the car standing still.

From what I understand, the launch is always electric because the DCT is direct drive. The ICE starts almost immediately if needed. The DCT shifts as needed by demand. It seems to me that it shifts as if the ICE were running even when it isn't. Since the motor can provide all or no torque as required, it doesn't need the trannie and doesn't change the torque it delivers anyway. Road speed and demand therefor keep the trannie in a gear that will suite the ICE.

A Sport mode at 60 HP wouldn't be very sporty.
 

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I'm confused, probably because "motor" seems to be used interspersed with "ICE".

Electric motors typically put out max torque at all reasonable RPM's, if called for. From what I understand the HEV motor puts out 43 HP and the PHEV 60 Hp. If it weren't for the ICE, a transmission would likely be unnecessary.

The ICE puts out 0 torque at 0 RPM so it needs a transmission of some sort. If the trannie is direct drive, it can't even run with the car standing still.

From what I understand, the launch is always electric because the DCT is direct drive. The ICE starts almost immediately if needed. The DCT shifts as needed by demand. It seems to me that it shifts as if the ICE were running even when it isn't. Since the motor can provide all or no torque as required, it doesn't need the trannie and doesn't change the torque it delivers anyway. Road speed and demand therefor keep the trannie in a gear that will suite the ICE.

A Sport mode at 60 HP wouldn't be very sporty.
Actually, an electric motor has 100% torque at zero RPM. Transmissions are necessary to match the RPM range of the motor to best fit automobile use.

I think you're understanding the flow well. I'm certain the PHEV is shifting the transmission when it feels the electric motor power is insufficient to supply what the throttle pedal is requesting, but feels a lower transmission gear would increase the torque multiplication of the motor to make it unnecessary to fire the ICE. That's the feeling I get when I push hard up a hill, but try to stay out of the ICE. There's a bit of a lag/hesitation, then the transmission shifts down and I can feel an increase in pull up the hill. It's not that the motor isn't putting out it's peak torque, it's that by using the transmission in a lower gear they get more applied power at the wheels, which is what acceleration is all about. Yes, a more powerful electric motor would eliminate the need, but there's a cost/benefit trade-off for a PHEV. A pure EV that has only the electric motor for power, so it has to have more available.
 

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I haven't seen any posts using the terms ICE and motor interchangeably or in the wrong context. The DCT can slip a clutch I believe under certain circumstances, for example shifting from reverse to forward without coming to a full stop. It is not clear if it is programmed to slip under other circumstances. Certainly the ICE clutch can slip.
 

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"Actually, an electric motor has 100% torque at zero RPM. Transmissions are necessary to match the RPM range of the motor to best fit automobile use."

I think this may be where I get confused since it isn't necessary to match motor RPM to auto use within reasonable limits. I think the trannie just does it to match ICE to car..... if or if not it's running; it's ready.

I also don't understand why the DCT would ever have to slip other than connecting/disconnecting the ICE. This begs the question, does reverse ever use the ICE? Reversing the motor is just switching. If the ICE isn't used in reverse, it would save a reverse gear.
 

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"The other rpm limiter is max Kwatts from the battery. The HEV and PHEV motor is the same, same torque rating. The difference is the PHEV has a larger, higher power rated battery which can drive the motor to higher RPMs thus more HP."

I think this one confused me as well. Maybe I don't understand torque vs HP in a constant torque motor. While HP does increase with RPM, the force (torque) remains essentially constant resulting in what would be a constant acceleration, discounting friction.... of all sorts.
 

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I also wonder what happens with the back EMF that electric motors generate at high RPM. In theory, the trannie would have to upshift for more power from the motor which is what it does but only when less power is called for.
 

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"Actually, an electric motor has 100% torque at zero RPM. Transmissions are necessary to match the RPM range of the motor to best fit automobile use."

I think this may be where I get confused since it isn't necessary to match motor RPM to auto use within reasonable limits. I think the trannie just does it to match ICE to car..... if or if not it's running; it's ready.
Ya got me. I didn't word that well. :D When I said transmission, I really meant gearbox. To my knowledge, all EVs use what they refer to as a single speed transmission, but it's really just a gearbox. The electric motor has an RPM range that most likely doesn't mesh well with a road going EV (either too low or too high a max RPM), so they use a gearbox to match the motor RPM better for a car's use. But it's not a transmission as we think of one, as it doesn't have multiple forward gears. Now does the gearbox provide reverse, or does the motor run backwards? I have no idea there, but either is possible. And yes, a trannie is a requirement for an ICE, since it can't replicate the torque and power curve of an electric motor.
 

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I jumped pretty hard on reverse yesterday and no ICE but it probably wasn't a good test. Scared me, and I'm fearless. I have also noticed that going very slow, even up a steep hill with 0 EV range, the ICE doesn't fire. I'm feeling more and more that the only clutch to wheels is ICE to trannie and the motor is direct drive to trannie and then wheels. There is no slip otherwise and the trannie just shifts to prep the drive train for ICT use and possibly to lower motor speed to reduce back EMF. Reverse is polarity only. Obviously there are clutches in the trannie itself but they are likely a stack of wet clutch plates one or the other always engaged.

Obviously this is full of shade tree reverse engineering. ....and likely full of something else.
 

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Actually, the fact the car can pull harder in reverse makes a pretty good case for the motor using the DCT for reverse gear, and not reversing the motor. Every transmission that I can ever recall looking at the gear ratios always had a much higher (numerically) ratio in reverse than any forward gear. This of course provides more power to the wheels and the feeling of faster acceleration. I don't know the exact power flow from the EV motor to the DCT, but yes the DCT itself has internal clutches, but I believe dry not wet. So regardless of where the EV motor is placed in the power stream, if it's going through the DCT it is passing through clutches of some kind.
 

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But once again that is ignoring the fact, and I believe it is a fact, that maximum torque from the motor is available at 0 RPM. The lower reverse gear that might or might not be available in the DCT wouldn't make a difference. Also clutches in the DCT might not disengage except for shifting ratios. One is always engaged. If the motor reversed, however, there might be other problems; lubrication, unusual stresses and the like.

This is definitely not your father's Oldsmobile.
 

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But once again that is ignoring the fact, and I believe it is a fact, that maximum torque from the motor is available at 0 RPM. The lower reverse gear that might or might not be available in the DCT wouldn't make a difference. Also clutches in the DCT might not disengage except for shifting ratios. One is always engaged. If the motor reversed, however, there might be other problems; lubrication, unusual stresses and the like.

This is definitely not your father's Oldsmobile.
Or Buick, or Pontiac... :D

However, it does make a difference. Yes, you are accurate that 100% torque is available at zero RPM. However, it's still only the torque that the motor is capable of providing. By using a transmission with a lower gear ratio, that same amount of torque is increased by the gearing of the transmission. Any ratio below 1:1 is going to increase the available torque applied to the wheels. The fact that the torque is available at zero RPM doesn't alter that.
 
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