Dual Motor EPA Certification Application (Reveals HP, Efficiency, Range, MPGe Figures)

[Trandall]

I was Hoping for more than 305 mile range from the 20" dual. I could probably get 305 in my LE at a steady 70 MPH in conserve. This tells my the enduro motors are only marginally more efficient than the quad... when it comes time to get another R1T this is gonna be a tough choice. I really don't need the 20" AT wheels except that I prefer the looks on the R1T.

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[Dark-Fx]

I could probably get 305 in my LE at a steady 70 MPH in conserve.

Maybe you'll get 340 miles with the dual motor.

 

[RexRemus]

If I'm reading the chart correctly, it would seem that the dual-motor R1S with 21" wheels, has a prospective adjusted combined EPA range rating of ~352 miles. That compares with 321 miles for the quad R1S on the same wheels, and is only about a 9.6% improvement.

While that's not trivial, it's quite a bit less than I would have expected in going from four motors down to two. Is one of the conclusions that the new Enduro motors are not particularly efficient?

Has anyone done the calculations for HP/Torque? on a per motor basis I have to assume you're getting pretty good efficiency. The dual motor setup gives nearly the same HP and better efficiency. If you took away half the current quad motors to make a dual motor variant you'd only be getting ~400hp - not 600-700. I'm not sure how it all works out but I feel like you can't get something for nothing - maybe running the enduros at 200ish HP each would give substantially more range, but that they are effectively giving more HP individually and still adding mileage, I don't know if it's a "failure" but I do agree, it might have been nice to see something more like 15% improvement, but I don wonder lb for lb how things shakeout if anyone has run the hard numbers

 

[izgoy]

Towing capacity hasn't changed by motor type, per Rivian's specs

So, 7700 lbs? If so, does it mean I can pull a trailer that has 7,500 lbs gross trailer weight? I've never pulled any trailer, so I need help understanding how this works.

 

[SamDoe1]

I expect the battery to be the limiting factor for straight line performance, but with individual motor torque vectoring it should mean a significant bump in responsiveness in corners and loose off-road, and I hope that's what is being planned.

I expect the tires to be the utmost limiting factor in any kind of performance metric for these vehicles. 840hp/900ftlb of torque out of the quad motors is an enormous figure and can/will easily roast the tires if it's not already metered out...especially so with the AT tires. Getting some really grippy wide tires will improve the performance out of the existing truck quite substantially though obviously at the cost of loose gravel and off road performance. Though that's something I personally don't really care about.

FWIW: The Rimac Nevera has 1800hp and uses 315 width rear, 275 front tires on sticky Michelin Pilot Sport 4s tires with nearly no side wall to get all that to the ground. Putting 1400hp through all terrain tires is an exercise in futility unless someone has some new ones in the pipeline.

I was Hoping for more than 305 mile range from the 20" dual. I could probably get 305 in my LE at a steady 70 MPH in conserve. This tells my the enduro motors are only marginally more efficient than the quad... when it comes time to get another R1T this is gonna be a tough choice. I really don't need the 20" AT wheels except that I prefer the looks on the R1T.

Power isn't free regardless of how many motors it comes from. The motors themselves could be similar or more in efficiency to the quad Bosch units but they still have to expend the same energy to move that weight through the air. This is why back when the ecoboost F150 came out everyone freaked out that the fuel economy was still sucky. Power isn't free and even with a V6, the turbo just crams in more air so there's more fuel to go bang to get that power. The advantage being that when you don't need it, you get better economy but that same principle applies to an EV in an easier to control manner.

I'm not at all surprised that the difference is marginal at best and will be a wash in actual practice. The big reason for dual vs quad is a cheaper purchase price for the consumer and, I'm assuming, a crap ton less in COGS for Rivian.

 

[zefram47]

We don't have long descents around here. Does the amount of cumulative energy put back in the battery seem to change if you're in conserve mode? Actual speed reduction seems fairly close to the same on flat ground here, which wouldn't be inverter related since you're only using half of them in conserve.

I haven't ever tried Conserve mode, so at the moment, no clue. I'll try to remember to give it a go in the near future and report back.

 

[dleepnw]

my eyes glazed over all the numbers but what I took away is the RUS seems to add about 500 lbs to the vehicles (7500 vs 7000), unless theres some other significant factor adding to the weight of the "All Terrain" package.

 

[Dark-Fx]

my eyes glazed over all the numbers but what I took away is the RUS seems to add about 500 lbs to the vehicles (7500 vs 7000), unless theres some other significant factor adding to the weight of the "All Terrain" package.

It's likely just rounded up to the nearest 500 lbs after accounting for driver weight.

 

[shrink]

my eyes glazed over all the numbers but what I took away is the RUS seems to add about 500 lbs to the vehicles (7500 vs 7000), unless theres some other significant factor adding to the weight of the "All Terrain" package.

I thought that, too, at first but @Dark-Fx pointed me in the right direction. See my post #25 in this thread.

 

[Adventusaurus]

We don't have long descents around here. Does the amount of cumulative energy put back in the battery seem to change if you're in conserve mode? Actual speed reduction seems fairly close to the same on flat ground here, which wouldn't be inverter related since you're only using half of them in conserve.

I can confirm that switching from conserve to all purpose, the amount of regen felt, and seen on the meter did not change. I changed drive modes specifically to try to get more regen on a long descent down the sierra nevada after the “reduced regen” warnings, and it didn’t work. Luckily on my drives from Tahoe I can generally just feather the brakes a couple of times in the whole drive. It’s not a huge deal for me. Slowing down helps too.

I’ve made the descent with various states of charge, from 30% to 70%. That doesn’t seem to make much, in any, difference either.

For amount of energy recovered, Iseem to recover the same on the descents by the %age meter, and use a little less on the flats in Conserve as expected.

 

[av8or]

There's been strong suspicion it's actually limited to the heat built up in the inverters rather than a battery limitation given the truck can sit on 200 kW at a DCFC for 15 minutes. So if Rivian improved cooling / efficiency with their homegrown inverters, they may be able to do more sustained regen than the quad. I'm pretty tired of losing regen every time I go down a canyon road.

I have a question about this. Do you lose it completely or does it reduce the regen? I live in a mountainous area and have tried to find the limits of the regen. I’ve never lost more than about 30% of regen and it’s always been able to slow down and stop the truck.

 

[zefram47]

I have a question about this. Do you lose it completely or does it reduce the regen? I live in a mountainous area and have tried to find the limits of the regen. I’ve never lost more than about 30% of regen and it’s always been able to slow down and stop the truck.

Eeh...I've had both. More recently it cuts about 50% and I'd say at lower speeds (40 mph or so) it would probably bring you to a stop, eventually. But when I first got the truck back in March it would cut probably 90% of the available regen and you absolutely had to use the brakes.

 

[av8or]

Eeh...I've had both. More recently it cuts about 50% and I'd say at lower speeds (40 mph or so) it would probably bring you to a stop, eventually. But when I first got the truck back in March it would cut probably 90% of the available regen and you absolutely had to use the brakes.

Thanks for the reply. I guessed 30% by what the dash says, but I agree it feels more like 50%.

 

[pc500]

They are an integrated motor/inverter so some drivetrain pairing efficiencies should help.

I don't necessarily expect them to be more efficient. I would expect however, that since there's only two of them, they would use less current than than is case with four motors. That should translate to greater range. While they do offer marginally greater range, it's quite a small improvement.

I understand that the relationship to power consumption is not linear in going from four to two motors. So while I wouldn't expect a 50% reduction in current used (and increased range), what we're apparently seeing from the dual motor seems fairly small, though still significant.

 

[HaveBlue]

Overall positive results and look, the battery now only self discharges less than 4% per month instead of 1% per day...

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