Dual Motor All Purpose not smooth now

[beatle]

I struggle with Kyles REALLY long videos like that. Thanks for watching all the way into it to find that nugget of information.

I really like that approach to solving the "AWD all the time". It keeps the EPA happy with a "key up" condition that matches testing, it gives the dual motor owners a way to have full time AWD without compromising stability control or throttle response, and it's "on brand" with other models in functionality. I'll be really happy to see that come through.

Yeah, I can't watch 2 hours of video to find the important details. It still sucks that we'll have to select AWD each time we drive to fix this issue. This wasn't a problem that needed to be fixed 8 months ago since the truck wasn't jerky when engaging the rear motor.

This solution is not consistent with any manufacturer that uses an induction motor since there is no need to physically disconnect them to prevent the drag. This means they can also effectively have the vehicle in "sport" mode all the time without resetting the drive mode.

Sponsored

 

[2kwik4u]

Yeah, I can't watch 2 hours of video to find the important details. It still sucks that we'll have to select AWD each time we drive to fix this issue. This wasn't a problem that needed to be fixed 8 months ago since the truck wasn't jerky when engaging the rear motor.

This solution is not consistent with any manufacturer that uses an induction motor since there is no need to physically disconnect them to prevent the drag. This means they can also effectively have the vehicle in "sport" mode all the time without resetting the drive mode.

Agreed. Wasn't like this when I bought it. Which means either it's a software change (most likely) or worn components. I'm not completely certain how they can justify a software change on that front and then still claim to not be able to have it "key up" in All Purpose because of EPA. Just doesn't quite jive with me.

Secondarily, I thought all of Rivians motors were Permanent Magnet not Induction. If that's correct, then you turn the motor into a generator if you don't feed it "some" power, so disconnecting it is the right answer. I struggle with the engineering selection of a dog clutch instead of some other method that could be more easily modulated to keep the smooth driveline feeling intact. I understand the dual motors have more stall torque than the quads, however there has to be a clutch pack based system that is capable of handling that torque load.

 

[beatle]

Correct, Rivian's motors are all permanent magnet. Tesla uses induction motors in the rear and doesn't have to deal with silly EPA key-up settings, clutches, or lock-up algorithms. Lucid has some other tricks in their PM motors that eliminate the need for disconnects.

 

[MountainBikeDude]

I struggle with Kyles REALLY long videos like that. Thanks for watching all the way into it to find that nugget of information.

I really like that approach to solving the "AWD all the time". It keeps the EPA happy with a "key up" condition that matches testing, it gives the dual motor owners a way to have full time AWD without compromising stability control or throttle response, and it's "on brand" with other models in functionality. I'll be really happy to see that come through.

Hahaha, took one for the community on that one.

I like that they aren't fully resetting it to key up, conserve mode, setting every drive, they essentially run a timer in the background, and provided you drive it again within 4 hours, I think they said, it will stay in that new AP AWD mode.

 

[CANCERDOC]

Hahaha, took one for the community on that one.

I like that they aren't fully resetting it to key up, conserve mode, setting every drive, they essentially run a timer in the background, and provided you drive it again within 4 hours, I think they said, it will stay in that new AP AWD mode.

This is not different than changing the drive modes (or suspension out of auto) now. Would be great if there is a little check box you can click to "acknowledge" that changing the drive modes or suspension heights would lead to lower efficiency, and let you just keep it there forever.

 

[iamnid]

Correct, Rivian's motors are all permanent magnet. Tesla uses induction motors in the rear and doesn't have to deal with silly EPA key-up settings, clutches, or lock-up algorithms. Lucid has some other tricks in their PM motors that eliminate the need for disconnects.

I think you have that switched. The rear in a tesla is permanent magnet and it's the primary motor. The front is induction which allows it to be turned on and off as necessary.

EDIT: I think you actually may be correct as it relates to the triple motor version of the cybertruck.

I really wish Rivian had done something similar. The "clunk" and delay while the rear motor is engaging feels and sounds awful and I can't imagine it's good for the clutch. I'd rather have the slightly lower efficiency of an induction motor and not have to worry about wear and tear on a clutch etc. and have a seamless transition from 2wd to 4wd

 

[beatle]

Yes, the Model S/X/CT has an induction rear, and 3/Y performance use induction front since they also sell a RWD 3/Y with a single PM motor, but they both have the same advantages.

I am surprised Rivian went the more complicated route with the disconnect. The Lightning has two PM motors that are always engaged. I really wonder just how much range Rivian gets by adding the disconnect, but I can't believe it's that much. Just annoying that everything EV is range driven, no pun intended.

 

[2kwik4u]

This is not different than changing the drive modes (or suspension out of auto) now. Would be great if there is a little check box you can click to "acknowledge" that changing the drive modes or suspension heights would lead to lower efficiency, and let you just keep it there forever.

I agree with this, and also confirm that's how it works now.

If I disable auto height (which I always do) on the way into work, then drive to lunch, then drive home, it doesn't reset until the next morning. Same on long road trips, once disabled it will stay that way "for the day" essentially. Just have to put it back the way I want it the next day.

I got used to always turning off the "Auto start/stop" in my Q7, this is no different. Sill annoying, but not the worst thing ever.

I also agree that a single "I get it, let me have lower efficiency" button, even once a month or something, would be a great addition.

 

[2kwik4u]

Just annoying that everything EV is range driven, no pun intended.

Yeap, this is super annoying. Sometimes user experience or driving dynamics should be allowed to win a battle.

Also, according to this......~18% better efficiency than a Silverado EV when similarly loaded. I'm unsure how that compares to the lightning, but I suspect it's similar.

 

[Jonger1150]

I think you have that switched. The rear in a tesla is permanent magnet and it's the primary motor. The front is induction which allows it to be turned on and off as necessary.

EDIT: I think you actually may be correct as it relates to the triple motor version of the cybertruck.

I really wish Rivian had done something similar. The "clunk" and delay while the rear motor is engaging feels and sounds awful and I can't imagine it's good for the clutch. I'd rather have the slightly lower efficiency of an induction motor and not have to worry about wear and tear on a clutch etc. and have a seamless transition from 2wd to 4wd

I'm running it in reduced traction just to avoid ruining the motor. There's no perceptible improvement to efficiency from 2025.51 from the previous update. This whole debacle started in February.

I will hit all-purpose every time I get it... but I'm not thrilled about it. Make AWD the default.

 

[beatle]

Yeap, this is super annoying. Sometimes user experience or driving dynamics should be allowed to win a battle.

Also, according to this......~18% better efficiency than a Silverado EV when similarly loaded. I'm unsure how that compares to the lightning, but I suspect it's similar.

That is kind of crazy since the truck has both motors permanently engaged when towing. There are a lot of other things that go into efficiency, and it's nice to see Rivian using those, but when range really matters (towing), the motor disconnect party trick can't even be used. The disconnect is only to get a higher EPA rated range for the brochure.

 

[ndmiller]

It's gotten really annoying starting from a light and when going from cruising to accelerating on the highway.....The rear motor engagement clunk wasn't there until a recent update. It has turned a pleasant driving experience into unpleasant as you can also feel the engagement.

 

[Jonger1150]

It's gotten really annoying starting from a light and when going from cruising to accelerating on the highway.....The rear motor engagement clunk wasn't there until a recent update. It has turned a pleasant driving experience into unpleasant as you can also feel the engagement.

Now that I know the AWD lock is coming it makes this all easier to stomach.

Can a Rivian employee with knowledge about what changed with 0.51 update chime in anonymously and tell us what was implemented secretly?

 

[Megaman0025]

Correct, Rivian's motors are all permanent magnet. Tesla uses induction motors in the rear and doesn't have to deal with silly EPA key-up settings, clutches, or lock-up algorithms. Lucid has some other tricks in their PM motors that eliminate the need for disconnects.

Tesla uses induction motors in the front, not the rear. And a permanent magnet in the rear.

 

[Jonger1150]

So.... let's hope this upgrade comes soon.

Taking bets. Will this be on the next update or not?

Sponsored