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ElectricTrucking

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Oooooooo. Did they say when the configurator would be updated to reflect this?

Also, good going everyone! We nagged then into submission! What say we try and get a 5-Seat version of the LE now?
I wanted to reach out with some great news! As of today, we can confirm that any customer with a saved Launch Edition configuration will soon have access to all five of the wheel options—including the dark options!!

Coming soon your configurator will be updated to include the 20 in dark and 22 in dark wheel options.

We will let you know when that becomes an option, so stay tuned!

Happy Friday!


Your fellow adventurer,
Sara
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Rhidan

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Rivian confirmed by email that the quad-motor system is full-time AWD, and the estimated ranges represent full-time AWD. I had assumed that, but the website omits anything about AWD. The website instead says things like the quad-motor system provides "exceptional efficiency in both off-road and on-road conditions." I had wondered if they would only run FWD or RWD as a sort of on-road "economy" mode to maximize range because the front/rear drive units can each put out 400+ hp. That might not make sense from a weight/powertrain perspective, but either way, Rivian confirmed full-time AWD.
 

skyote

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Rivian confirmed by email that the quad-motor system is full-time AWD, and the estimated ranges represent full-time AWD. I had assumed that, but the website omits anything about AWD. The website instead says things like the quad-motor system provides "exceptional efficiency in both off-road and on-road conditions." I had wondered if they would only run FWD or RWD as a sort of on-road "economy" mode to maximize range because the front/rear drive units can each put out 400+ hp. That might not make sense from a weight/powertrain perspective, but either way, Rivian confirmed full-time AWD.
I spoke to Charles Sanderson, Chief Engineer @ Rivian, in February at Fully Charged Live. He said that it would become 2wd on the highway for efficiency, and actually described the mechanics of doing it.

This could have changed, but it sounded like quite a bit of engineering went into the design & capability, so I doubt it.

Personally, I've seen too many instances of incorrect info coming from support/CS, so I wouldn't always take what they say at face value.
 

azbill

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I spoke to Charles Sanderson, Chief Engineer @ Rivian, in February at Fully Charged Live. He said that it would become 2wd on the highway for efficiency, and actually described the mechanics of doing it.

This could have changed, but it sounded like quite a bit of engineering went into the design & capability, so I doubt it.

Personally, I've seen too many instances of incorrect info coming from support/CS, so I wouldn't always take what they say at face value.
From an engineering standpoint, that is only possible if the motors on one axle can be declutched from the wheels. Otherwise the motors BEMF (back electromagnetic force) add extra drag. Even then it is not likely to be more efficient than apply less power to each wheel individually to overcome the rolling friction.
 

skyote

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From an engineering standpoint, that is only possible if the motors on one axle can be declutched from the wheels. Otherwise the motors BEMF (back electromagnetic force) add extra drag. Even then it is not likely to be more efficient than apply less power to each wheel individually to overcome the rolling friction.
I'm trying to find my post from after the event, when the details were more fresh on my mind. Pretty sure it's the rear wheels that will disconnect & that the magic is in the gearbox, taking the motors out of play.

Edit - Can't find that damn post, but remember him talking about requiring the ability to very quickly "reconnect" when needed, and he used his hands when describing how it worked.
 
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MReda

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For the sake of semantics (because it's the internet!), there is nothing that says "full time AWD" can't also run in 2WD mode at certain times for efficiency. As long as the idle motors (I agree with @azbill, it seems they'd probably have to be disengaged to really make it worth it, but I'd be interested in the technology to learn otherwise) can be engaged in response to changing road conditions at a high enough speed to correct for slipping on the other end of the vehicle, it would be transparent to the user.

The Haldex system used on transverse mounted VAG cars (and the R8) comes to mind. Of course, a lot of people out there would claim that isn't AWD, but 4WD, and arguments ensue.
 

Rhidan

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I spoke to Charles Sanderson, Chief Engineer @ Rivian, in February at Fully Charged Live. He said that it would become 2wd on the highway for efficiency, and actually described the mechanics of doing it.

This could have changed, but it sounded like quite a bit of engineering went into the design & capability, so I doubt it.

Personally, I've seen too many instances of incorrect info coming from support/CS, so I wouldn't always take what they say at face value.
Interesting. Yes, CS did not give me any details that would add to the credibility of their confirmation. Sounds like you may have received better insight into at least what Rivian planned to do. I had searched the forum, but didn’t see anything on this topic. I thought it was notable the website did not claim AWD, and it seemed at least initially intuitive that you could increase efficiency by switching to 4 x 2. I wondered if a quad-motor BEV could accomplish the switch without a mechanical transfer case. That then got me thinking whether the advertised range numbers might not reflect full time AWD. A big rabbit hole thought experiment to pass the time.

I am not close to anything resembling an engineer, but couldn’t you reduce the drag by using pure induction motors in the rear that turn off? Maybe I’m getting too far ahead. We obviously won’t know until Rivian releases more info. I’m just hyped about the different things you can do with a quad motor system.
 

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Received following email from Rivian:
"I have some more updated information for you in regards to your question about our outlets in our vehicles. After speaking with my design team, I have learned that our 110v outlets are rated to 15A "
 

ajdelange

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I am not close to anything resembling an engineer, but couldn’t you reduce the drag by using pure induction motors in the rear that turn off?
The Rivians, AFAIK, use synchronous PM motors. None the less they can be controlled to produce torque against or with the direction of shaft rotation and that means a torque of 0. Zero torque means the motor is "turned off". It is, however, still mechanically connected to the wheels so that the drive gears are still being warmed whenever the vehicle is moving.

The art here is is "vectoring" the torque to the 4 motors in such way that vehicle stability is insured and that maximum efficiency is obtained.
 

ajdelange

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Received following email from Rivian:
"I have some more updated information for you in regards to your question about our outlets in our vehicles. After speaking with my design team, I have learned that our 110v outlets are rated to 15A "
Bummer that it is 110 instead of 120/240 and bummer that it is only 15 Amps but that's not bad really for most "adventure" type applications. May lock out some tools at a jobsite but not most appliances at a campsite. The thing never was marketed as a work truck.
 

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slawwach

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Bummer that it is 110 instead of 120/240 and bummer that it is only 15 Amps but that's not bad really for most "adventure" type applications. May lock out some tools at a jobsite but not most appliances at a campsite. The thing never was marketed as a work truck.
Before I got this response there were rumors that outlets will provide 400W only, so though more power would be appreciated, I was actually quite happy that it's 15A.
It will be enough to power most camping equipment I can think of.
 

timesinks

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Before I got this response there were rumors that outlets will provide 400W only, so though more power would be appreciated, I was actually quite happy that it's 15A.
It will be enough to power most camping equipment I can think of.
Those rumors never made any sense -- the induction cooktop featured in the camp kitchen is going to draw substantially more than 400W.
 

Lmirafuente

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The Rivians, AFAIK, use synchronous PM motors. None the less they can be controlled to produce torque against or with the direction of shaft rotation and that means a torque of 0. Zero torque means the motor is "turned off". It is, however, still mechanically connected to the wheels so that the drive gears are still being warmed whenever the vehicle is moving.

The art here is is "vectoring" the torque to the 4 motors in such way that vehicle stability is insured and that maximum efficiency is obtained.
Question...and showing my age here...back during driver's ed...when a rear wheel drive car starts to veers off the pavement, we were told to coast completely off and apply breaks when off the road. With the Rivian, and the above info...do we no longer do that now? I only ask because when I first drove a front-wheel drive vehicle in the snow and the back of the car started to slide, I first started to take my foot off the gas...but after a few spin outs...I decided to accelerate...and viola! all was good after that...

Looking forward to the answer, and it is my thinking we drive normally regardless of the terrain ---thoughts?
 

ajdelange

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Anti lock braking has been the norm for many years now. Think of what these cars will do as anti lock braking plus the ability to apply differential thrust in the forward direction as well a rear ward. The answer to you question is no - you no longer do that. If you want to slow down you take your foot off the accelerator. If you want to slow down more than the regen will handle you step on the brake.
 

Lmirafuente

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Anti lock braking has been the norm for many years now. Think of what these cars will do as anti lock braking plus the ability to apply differential thrust in the forward direction as well a rear ward. The answer to you question is no - you no longer do that. If you want to slow down you take your foot off the accelerator. If you want to slow down more than the regen will handle you step on the brake.
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