What about us who just want the single motor?

[Deleted member 12457]

Warning: I wrote a LONG post to show how a single drive unit taken directly from a Model 3 would affect the performance of a Cybertruck single motor (aka CT-1) going up a mountain highway under various scenarios and loads. It's really long and you might not want to read it, but that's fine. The TL;DR is that it's not a problem, and even less so with the improvements Tesla has made to the Model 3 motor (as seen right now in the Model Y). I omitted all the physics calculations to avoid overloading more than I have. If anybody finds any errors or calculates differently, let me know.

... (sorry, I did read it all but shortened it for my response)

Traction for steering or pulling could be an issue with a single motor, RWD Cybertruck if driving through very uneven or soft terrain. There will also be a slight reduction in motor horsepower and torque at lower battery SOCs (as can be seen from the Mountain Pass Performance dyno tests that I linked above). Go look up Ford F150 specs (Ford has nice PDFs on their website that list all the specs) as far as engine HP, torque, curb weight, GVWR, towing capacities and see how those compare. I did, and do not see any problems with using a single Model 3 drive unit on a CT-1, except that the top speed going up a 10% grade would be limited to 60 MPH at the absolute maximum GCWR (Gross Combined Weight Rating), which would likely be around 17,000 lbs for the CT-1. With some enhancement to the drive unit (like what is already on the Model Y drive units), Tesla would add a bit more horsepower to the single motor (likely to around 345 HP) and that would add a little more top end speed to the CT-1 while under the maximum loads.

With all of this in mind I have to wonder why Tesla went for four-motor when a 2- and 3-motor design is more than enough based on your calculations. I assume some of it is the pinky problem or trying to one up other EV vendors with lower quality motors. If a one-motor design is enough for everything except pulling heavy loads, the two-motor takes care of that problem, so even a three-motor is a waste and only for drag strips. Of course the weight of the CT could be much more than you're calculating, messing up your calculations. That said, my two-motor reservation should be absolutely fine for everything I want to do. Of course I'd like to have a 500-mile range. I just drove (in my terrible gas mileage Tacoma) 700 miles in one day (13.5 hrs with multiple stopes) so having a 400-500 mile max would have let me stop for lunch and charging just once. I got less than 20 mpg so needed to stop for gas three times. Filling up in California at $4.50/gal about killed me.

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[JBee]

With all of this in mind I have to wonder why Tesla went for four-motor when a 2- and 3-motor design is more than enough based on your calculations. I assume some of it is the pinky problem or trying to one up other EV vendors with lower quality motors. If a one-motor design is enough for everything except pulling heavy loads, the two-motor takes care of that problem, so even a three-motor is a waste and only for drag strips. Of course the weight of the CT could be much more than you're calculating, messing up your calculations. That said, my two-motor reservation should be absolutely fine for everything I want to do. Of course I'd like to have a 500-mile range. I just drove (in my terrible gas mileage Tacoma) 700 miles in one day (13.5 hrs with multiple stopes) so having a 400-500 mile max would have let me stop for lunch and charging just once. I got less than 20 mpg so needed to stop for gas three times. Filling up in California at $4.50/gal about killed me.

You need to disassociate vehicle performance from how many motors it has.

The primary reason for quad motor is torque vectoring capability without using any differentials. It's highly likely all the CT motors will be the same as used in the Plaid. In mass production these will likely be cheaper to manufacture than the M3/MY motors, and will substantially save weight and size. Electric motors are mostly scalable, that means you can change the motor size to fit the application power required and not just change how many motors you have.

Because of this, to be honest, I cannot see that the single motor will see production at all.

 

[android04]

With all of this in mind I have to wonder why Tesla went for four-motor when a 2- and 3-motor design is more than enough based on your calculations. I assume some of it is the pinky problem or trying to one up other EV vendors with lower quality motors. If a one-motor design is enough for everything except pulling heavy loads, the two-motor takes care of that problem, so even a three-motor is a waste and only for drag strips. Of course the weight of the CT could be much more than you're calculating, messing up your calculations. That said, my two-motor reservation should be absolutely fine for everything I want to do. Of course I'd like to have a 500-mile range. I just drove (in my terrible gas mileage Tacoma) 700 miles in one day (13.5 hrs with multiple stopes) so having a 400-500 mile max would have let me stop for lunch and charging just once. I got less than 20 mpg so needed to stop for gas three times. Filling up in California at $4.50/gal about killed me.

Like Elon Musk has said before, they don't make slow cars. There could be other reasons to use more motors as well that we don't know about. Perhaps Tesla wants to use torque vectoring at each independent wheel in order to be able to safely handle heavy loads, especially if the suspension will be of a type that isn't normally used for trucks due to drawbacks in handling those heavy loads. Perhaps Tesla wants to use more smaller, more efficient motors instead of bigger, more powerful motors. Maybe they wanted to one-up Crab Mode and Tank Turn.

I wanted the performance and range of the Tri motor, but if the price is too high I'd settle for the Dual motor. That is still a tiny bit faster than my Model 3 LR RWD, with the same range (I don't really need more range), and more utility and durability. And the AWD would be nice to have in many situations driving on unpaved surfaces.

 

[Deleted member 12457]

Like Elon Musk has said before, they don't make slow cars. There could be other reasons to use more motors as well that we don't know about. Perhaps Tesla wants to use torque vectoring at each independent wheel in order to be able to safely handle heavy loads, especially if the suspension will be of a type that isn't normally used for trucks due to drawbacks in handling those heavy loads. Perhaps Tesla wants to use more smaller, more efficient motors instead of bigger, more powerful motors. Maybe they wanted to one-up Crab Mode and Tank Turn.

I wanted the performance and range of the Tri motor, but if the price is too high I'd settle for the Dual motor. That is still a tiny bit faster than my Model 3 LR RWD, with the same range (I don't really need more range), and more utility and durability. And the AWD would be nice to have in many situations driving on unpaved surfaces.

I thought I saw an article awhile ago saying the Semi would use four Model 3 motors. Now they want to put four motors in a CT yet they aren't saying a CT could pull an 80K lb load.

 

[JBee]

I strongly suspect all Tesla models will eventually transition to the Plaid CF wrapped motors. Including Semi, Roadster, M3, MY, MX, MS and M2/Van when they come around. If I had made the most power dense and efficient electric motor at a low cost, I'd be putting it in every model too.

 

[android04]

I strongly suspect all Tesla models will eventually transition to the Plaid CF wrapped motors. Including Semi, Roadster, M3, MY, MX, MS and M2/Van when they come around. If I had made the most power dense and efficient electric motor at a low cost, I'd be putting it in every model too.

I sure hope so! As long as they can manufacture it just as easily, it doesn't add unreliability, and doesn't cost much more than the non-CF motor.

 

[JBee]

I sure hope so! As long as they can manufacture it just as easily, it doesn't add unreliability, and doesn't cost much more than the non-CF motor.

Theres a heap of things that have been designed out of the CRIM. Especially the magnets which made manufacturing hard (degaussing) and expensive. The CF wrap means less materials and weight, therefore cost, without negatively impacting performance and can streamline production accross the range.

 

[FutureBoy]

I thought I saw an article awhile ago saying the Semi would use four Model 3 motors. Now they want to put four motors in a CT yet they aren't saying a CT could pull an 80K lb load.

Motor torque isn’t the only requirement for being able to pull 80k lb loads. Give the CT front dailies and rear triples (to get the 10 wheels of a big rig tractor) and an 80k lb load might be feasible. If the exoskeleton doesn’t crumple. The steering might be pretty messed up too with all those wheels.

 

[android04]

TL;DR fixed a few mistakes from my previous post, but newer Model 3 and Y use less powerful rear motors than my older Model 3 LR RWD. A single rear motor used in CT-1 (old nor new) would not be powerful enough to handle towing up a 10% grade at an acceptable speed with max towing and max payload. May be why Tesla could switch instead to more motors that are less powerful but more efficient, and why CT-2 could possibly be the base model.

I revisited my calculations to tweak a few things. I previously used the same amount of energy for all CT-1 calculations that it took to keep my Model 3 going 60 MPH on a flat road. At worst, more likely the CT-1 will require 2x the amount of energy to maintain the same speed because it is bigger and heavier. I also increased the energy again when towing a load to account for the added weight and friction of a 7,500 lb trailer (used 1.5x the amount of energy than the CT-1 by itself). So Model 3 takes 20 kW to maintain the 60 MPH on a flat road, 40 kW for the CT-1 by itself or at max payload, and 60 kW for the CT-1 and max towing (whether max payload added or not). I used the HP numbers from MPP that they measured on their Model 3 LR RWD with a dyno, but Tesla's official number is a little lower. The official number is 211 kW or 283 HP for the rear motor, so I will use that number instead. I also fixed an error in adding the CT-1 maximum gross combined weights and it should be 16k lbs, not 17k lbs.

Based on the tweaks I made, here are the new results for going 60 MPH on a 10% grade:
0. Model 3 LR RWD at 4030 lbs (driver + car) takes 68.06 kW (91.27 HP)
1. CT-1 at 6000 lb (driver + truck) takes 111.56 kW (149.61 HP)
2. CT-1 at 9500 lb (driver + truck + max payload) takes 153.29 kW (205.56 HP)
3. CT-1 at 13500 lb (driver + truck + max towing) takes 221.01 kW (296.38 HP)
4. CT-1 at 16000 lb (driver + truck + max towing + max payload - tongue weight) takes 250.82 kW (336.36 HP)

If we use the official 211 kW rating of the rear motor in Model 3 LR RWD, then CT-1 with max towing load (@ 13,500 lbs) will not be able to go 60 MPH up that mountain road. It will instead be limited to 55 MPH. The CT-1 with max towing and max payload (@ 16,000 lbs) will only be able to go 46 MPH.

This could be a reason why Tesla might opt to get rid of the single motor CT-1 and instead make the dual motor CT-2 the base model (not saying they will, but might in order to ensure that it performs acceptably in all the rated capacities). In my previous long post I also stated that I believed the Model Y motors have been improved by making them more powerful over the Model 3 motors, but this is actually not the case. I looked through official EPA documents and the Model Y and newer Model 3 vehicles actually have lower power ratings on their rear motors. My Model 3 LR RWD rear motor is officially rated at 211 kW, but the newer Model 3 rear motors are 198 kW for SR+, 195kW for LR AWD, and 190 kW for LR Performance. The Model Y rear motors are 201 kW for the LR AWD and 179 kW for the LR Performance. Yes, the Performance trims of 3 and Y have lower ratings on the rear because their front motors get a higher rating than the LR AWD to make up for it. So it seems like Tesla has moved to lower power ratings for their motors possibly due to efficiency, and may plan to use the same methodology for the Cybertruck. With 2 motors, people will be able to drive 75 MPH up a mountain road while towing a 7,500 lb trailer and hauling a 2,500 lb payload with their base model CT. Hopefully the prices shown at the unveiling stay the same.

 

[Deleted member 12457]

Motor torque isn’t the only requirement for being able to pull 80k lb loads. Give the CT front dailies and rear triples (to get the 10 wheels of a big rig tractor) and an 80k lb load might be feasible. If the exoskeleton doesn’t crumple. The steering might be pretty messed up too with all those wheels.

Dualies? (As in two wheels on each end of the axle.) Let's get a little real with the rear end as well. Trucks have two wheels up front and four pairs of wheels on the rear end. The front wheels are not powered, used only for steering. The rear end would be the equivalent of four Model 3 RWD's with the wheels together, as in "dualie." Here's a rendering showing four rear wheels so just double them up. This could be a nice fifth-wheeler towing CT but as you say, don't believe it has the structure to support and tow a 53-foot loaded trailer.

@android4 Do you think four adapted Model 3 RWD motors could deliver the goods in this configuration?

 

[Throwcomputer]

Dualies? (As in two wheels on each end of the axle.) Let's get a little real with the rear end as well. Trucks have two wheels up front and four pairs of wheels on the rear end. The front wheels are not powered, used only for steering. The rear end would be the equivalent of four Model 3 RWD's with the wheels together, as in "dualie." Here's a rendering showing four rear wheels so just double them up. This could be a nice fifth-wheeler towing CT but as you say, don't believe it has the structure to support and tow a 53-foot loaded trailer.

@android4 Do you think four adapted Model 3 RWD motors could deliver the goods in this configuration?

Encroaching into El Camino territory! Truck version of el camino. hahahah!

 

[Deleted member 12457]

Encroaching into El Camino territory! Truck version of el camino. hahahah!

This work better? Not so long? Forgive my poor edits. This could be a good fifth-wheeler tower as well as for flat bed trailers.

 

[firsttruck]

Dualies? (As in two wheels on each end of the axle.) Let's get a little real with the rear end as well. Trucks have two wheels up front and four pairs of wheels on the rear end. The front wheels are not powered, used only for steering. The rear end would be the equivalent of four Model 3 RWD's with the wheels together, as in "dualie." Here's a rendering showing four rear wheels so just double them up. This could be a nice fifth-wheeler towing CT but as you say, don't believe it has the structure to support and tow a 53-foot loaded trailer.

@android4 Do you think four adapted Model 3 RWD motors could deliver the goods in this configuration?

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Even the largest Ford Super Duty F-550 & F-600 trucks only need one set of dualies (one axle with 4 wheels) to reach towing capacities of 30,000- 33,500 lbs

2021 Ford Super Duty Chassis Cab Trailer Towing Selector
https://www.ford.com/cmslibs/conten...df/guides/21Towing_Ford_SuperDuty_CC_Dec3.pdf


Why would Cybertruck Max Duty need dual dualies (two axles with four wheels each) in the rear?

 

[Deleted member 12457]

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Even the largest Ford Super Duty F-550 & F-600 trucks only need one set of dualies (one axle with 4 wheels) to reach towing capacities of 30,000- 33,500 lbs

2021 Ford Super Duty Chassis Cab Trailer Towing Selector
https://www.ford.com/cmslibs/conten...df/guides/21Towing_Ford_SuperDuty_CC_Dec3.pdf


Why would Cybertruck Max Duty need dual dualies (two axles with four wheels each) in the rear?

To hold four motors since two would not be enough.

The F-600 uses a huge 6-7L V8. The dual set of dualies allows for better trailer tongue carrying. The photo shows the truck porpoising caused by too much tongue weight. I'm making that judgment based on the slightly wider gap between the front tire and the body. There are plenty of commercial trucks that only use two axles instead of three but I believe Tesla is designing the Semi to tow commercial trailer rigs with a typical post mounted between the two rear axles.

 

[firsttruck]

To hold four motors since two would not be enough.

The F-600 uses a huge 6-7L V8. The dual set of dualies allows for better trailer tongue carrying. The photo shows the truck porpoising caused by too much tongue weight. I'm making that judgment based on the slightly wider gap between the front tire and the body. There are plenty of commercial trucks that only use two axles instead of three but I believe Tesla is designing the Semi to tow commercial trailer rigs with a typical post mounted between the two rear axles.

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2022 Ford Super Duty POWER
https://www.ford.com/trucks/super-duty/features/power/

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2017 3/4-Ton Premium Truck Challenge: Diesels on the Dyno
Posted by Mark Williams | May 1, 2017
https://news.pickuptrucks.com/2017/05/2017-34-ton-premium-truck-challenge-diesels-on-the-dyno.html

.....
Power to the Rear Wheels
The Chevy's all-new turbo-diesel 6.6-liter V-8 Duramax made the most horsepower and torque of our four players, recording 385 peak hp and 775 pounds-feet of torque on the chassis dyno. This was just slightly ahead of the Ford's 6.7-liter V-8 Power Stroke, which made 369 hp and 721 pounds-feet of torque. Ram's 6.7-liter inline-six-cylinder Cummins came in third with 332 hp at 2,700 rpm, and 663 pounds-feet of torque at 2,200 rpm. The Nissan's 5.0-liter V-8 - the smallest engine of the group — came in last, making 267 hp and 437 pounds-feet of torque.

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Watch A Tesla Model S Plaid Almost Break A Dyno
Jul 26, 2021 by Martin Bigg
https://carbuzz.com/news/watch-a-tesla-model-s-plaid-almost-break-a-dyno

.....
Model S Plaid will generate over 1,000 horsepower to the wheels, suggesting that it could be even more powerful than Tesla claims.

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Tesla Model S Plaid has three carbon fiber wrapped motors for total about 1,020 horsepower and 1,050 lb-ft of torque at the wheels.

If using those motors in truck you use a gear ratio for lower top speed but more torque at wheels.
The Model S Plaid is beating most 1,000hp supercars.

Won't two Model S Plaid motors (approx 660 hp) geared for truck use give more towing power than Ford 6.7L V8 diesel?

If the Cybertruck Max Duty needs more power add dual motors in the front.

Also there is speculation that each carbon wrapped motor can output 400hp but that the old style batteries ( NOT 4680s) in the current Model S Plaid can not supply the needed current. That should not be an issue with the Cybertruck.

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