SPECIAL EDITION QUAD-MOTOR Cybertruck rumor

[Crissa]

Tesla's system of multiple motors is to have each motor provide a different torque curve.

That means at the low end, it can apply all the motors it needs - and at the high end, it can disengage the motors it doesn't need.

Rivian and Lordstown are using a system where that's not really possible. Lordstown's truck will have to use all the motors, all the time, or end up with weird drag issues and uneven power. I think Rivian has a method of spreading power across an axle, but I really don't know.

And no one has been under a Cybertruck, so we have no idea what they'll do with the two motors in the back. But it will have electronic braking which allows you to shift power from wheel to wheel using the differential's natural inclination.

-Crissa

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[MEDICALJMP]

I get that you are smoking some real good shit if you think the Cybertruck is going to have a CD of .25. Pass it over man!

According to this article the Cybertruck is fairly efficient for this class of vehicle. The estimate is CD 0.36 for CT where the Ram 1500 is 0.56 and the F150 is 0.59 CD. ‘’While Tesla hasn’t provided an official drag value yet, Elon Musk has said that “with extreme effort, Cybertruck might hit a 0.30 drag coefficient, which would be insane for a truck.””

https://thenextweb.com/plugged/2019...rucks-aerodynamics-compare-to-regular-trucks/

I have read in another analysis that the CT design with the tonneau cover closed acts as an airfoil. Let’s be honest. This isn’t going to be a fighter jet, but best in class isn’t far fetched.

 

[CappyJax]

There are several real world examples of EVs towing that resulted in about 50% reduction in range. Real world towing examples from ICE trucks pulling 10K-14K lbs trailers are similar (40% reduction). So based on this info & the difference in Cybertruck I have posited that Cybertruck towing might be around a 50% reduction even at 14,000 lbs.

Your prediction of 2,000Wh/mi. that you claim to have made scientifically using your spreadsheet is way out of range.

I don't think anyone should rely on that claim without more validation.
If you do not want to backup it up with anything that is fine too.

Carl Sagan: Extraordinary Claims Require Extraordinary Evidence

Show me an EV pulling a 14,000 pound 5th wheel losing only 50% of their range. Show me evidence of an ICE vehicle only losing 40% of range pulling a similar trailer.

I provided the evidence in the form of actual physics. Now you provide evidence of your claims.

 

[TVBtesla]

I heard Elon tell Joe rogan he would be driving a plaid CYBRTRK, my 1st or 2nd will be one when available

 

[firsttruck]

Show me an EV pulling a 14,000 pound 5th wheel losing only 50% of their range. Show me evidence of an ICE vehicle only losing 40% of range pulling a similar trailer.

I provided the evidence in the form of actual physics. Now you provide evidence of your claims.

The actual physics of energy use per mile does not care if vehicles are BEV (kwh) or ICE (mpg). If same total weight (tow vehicle + trailer), same cD, same frontal area you get same answer from formulas.
If ICE + trailer total weight is 14,000lbs, cD .55, frontal area X has 40% mpg loss.
then BEV + trailer total weight is 14,000lbs, cD .55, frontal area X will have same 40% kwh loss.

Below are examples of how much worse energy use is (40-50%) when towing large trailers.
Even shows how towing 5th wheel trailer is more energy effecient than similar ball hitch travel trailer.

------------

Ford F-150, curb weight 4,995lbs, non-towing range 15-18 mpg

Ford F150 that tows 10,000 lbs., Eco-Boost - iRV2 Forums
https://www.irv2.com/forums/f45/ford-f150-that-tows-10-000-lbs-eco-boost-433691.html
03-08-2019, 10:04 AM #11
tscarps, Senior Member, Location: Omaha, NE
Mallard travel trailer with a dry weight of roughly 8,000 lbs. loaded up closer to 9,000.
total 14,000 lbs
towing the Mallard travel trailer got about 8 mpg.

Open Roads Forum - Travel trailer "vs" fith wheel -- MPG to tow
2016
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29131182/print/true.cfm
Posted By: Padlin on 12/18/16 05:10am
both trailers were 10.5 ft high
5th wheel trailer was 1 ft longer, 2" wider and 900lbs heavier.
10 mpg ball hitch Travel Trailer, 20 ft, 3,500 lbs, 10.5 ft high
13 mpg 5th wheel trailer, 21 ft, 4,400 lbs, 10.5 ft high, 2 inches wider
17 mpg without trailer
17 mpg is more than 40% better than 10mpg

.....
Posted By: StirCrazy on 12/20/16 12:51am
my experience was similar to a couple.
towing old travel trailer (29 foot, 7500 lbs) with my 99 7.3I got about 11.4 mpg.
same truck a month later with a new 38-foot, 5th wheel 11,500 lbs trailer I got 15.7 mpg. exact same trip route. As mentioned the more aerodynamic front end of the 5th and being closer to the truck cab makes only one drag zone instead of two with the typical ball hitch travel trailer.


------------

From your spreadsheet what answer do you get for

1. total weight: 11,000 lbs ( 4,990 kg )

--- (tow vehicle, 2 people (400lbs), bags (400lbs), misc stuff (120 lbs), trailer ( 6,000lbs)


2. Coefficient of drag for tow vehicle: 0.25

3. Coefficient of drag for trailer: 0.55

4. area of front of tow vehicle: 25 square ft ( 2.31 sq meters )

5. area of front of trailer: 76.5 sq ft ( 7.124 sq meters = 2.60m x 2.74m)

6. speed: 56 mph ( 90 k/h )

 

[CappyJax]

The actual physics of energy use per mile does not care if vehicles are BEV (kwh) or ICE (mpg). If same total weight, cD, frontal area you get same answer from formulas.
If ICE + trailer total weight is 14,000lbs, cD .55, frontal area X has 40% mpg loss.
then BEV + trailer total weight is 14,000lbs, cD .55, frontal area X will have same 40% kwh loss.

Below are examples of how much worse energy use is (40-50%) when towing large trailers.
Even shows how towing 5th wheel trailer is more energy effecient than similar ball hitch travel trailer.

------------

Ford F-150, curb weight 4,995lbs, non-towing range 15-18 mpg

Ford F150 that tows 10,000 lbs., Eco-Boost - iRV2 Forums
https://www.irv2.com/forums/f45/ford-f150-that-tows-10-000-lbs-eco-boost-433691.html
03-08-2019, 10:04 AM #11
tscarps, Senior Member, Location: Omaha, NE
Mallard travel trailer with a dry weight of roughly 8,000 lbs. loaded up closer to 9,000.
total 14,000 lbs
towing the Mallard travel trailer got about 8 mpg.

Open Roads Forum - Travel trailer "vs" fith wheel -- MPG to tow
2016
https://www.rv.net/forum/index.cfm/fuseaction/thread/tid/29131182/print/true.cfm
Posted By: Padlin on 12/18/16 05:10am
both trailers were 10.5 ft high
5th wheel trailer was 1 ft longer, 2" wider and 900lbs heavier.
10 mpg ball hitch Travel Trailer, 20 ft, 3,500 lbs, 10.5 ft high
13 mpg 5th wheel trailer, 21 ft, 4,400 lbs, 10.5 ft high, 2 inches wider
17 mpg without trailer
17 mpg is more than 40% better than 10mpg

.....
Posted By: StirCrazy on 12/20/16 12:51am
my experience was similar to a couple.
towing old travel trailer (29 foot, 7500 lbs) with my 99 7.3I got about 11.4 mpg.
same truck a month later with a new 38-foot, 5th wheel 11,500 lbs trailer I got 15.7 mpg. exact same trip route. As mentioned the more aerodynamic front end of the 5th and being closer to the truck cab makes only one drag zone instead of two with the typical ball hitch travel trailer.


------------

From your spreadsheet what answer do you get for

1. total weight: 11,000 lbs ( 4,990 kg )

--- (tow vehicle, 2 people (400lbs), bags (400lbs), misc stuff (120 lbs), trailer ( 6,000lbs)


2. Coefficient of drag for tow vehicle: 0.25

3. Coefficient of drag for trailer: 0.55

4. area of front of tow vehicle: 25 square ft ( 2.31 sq meters )

5. area of front of trailer: 76.5 sq ft ( 7.124 sq meters = 2.60m x 2.74m)

6. speed: 56 mph ( 90 k/h )

Anecdotal stories are not evidence. And if an ICE loses 40% of its range, the BEV will lose more because the BEV does not use energy to maintain combustion. Therefore, an ICE doesn’t use twice the fuel for twice the power to the wheels, it uses something less. In addition, ICE engines are often more efficient at higher power settings.

 

[firsttruck]

Anecdotal stories are not evidence.

There is way more real world DATA like that.

You can get the same 40% loss seen in real world ICE non-tow vs tow using physics formulas.
If that was NOT true what would be value of using the formulas.
If the formulas are good then they help us understand the real world and predict what might happen in the real world. That is what science tries to do.

the BEV will lose more because the BEV does not use energy to maintain combustion.

"maintain combustion" & " ICE engines are often more efficient at higher power settings" is nothing special. At a steady speed it is just one of many constant & consistent factors that are all summed up in total energy to wheels efficiency that provided the traction. You have similar loss factors in BEV. We do not worry about every individual bearing loss in the many many more bearings in ICE vs BEV. We use the total efficiency of about 35% for ICE & 85% for BEV.

 

[Crissa]

Yeah, of course!

When slipping, torque doesn't help. Nor does it help with range! That's why you'd want to be able to change the amount of power required to produce the least amount of torque needed - then put it where you need it,

Anecdotal stories are not evidence. ...

Yeah, BEVs technically are using no more power to do most things (except provide heat) because an ICE is always wasting power idling or providing the wrong amount of torque. A BEV stuck in traffic is not losing range, but an ICE is. It still takes just as much power to move the same trailer. You just notice it more because the BEV is so efficient otherwise (and contains so little energy).

As an example, my motorcycle contains 1/4 gallon of gas in energy. But it can get 80 miles range! Sure it only goes half that at freeway speed - but that's because air resistance. It's not like an ICE bike magically is doing better - if it went its optimum speed (instead of freeway speed) it would go twice its range, too. My spouse's scrambler get 50mpg and contains two gallons. You ride it at freeway speed and you're only going to get 80 miles. Ride it in the moutains here and you can go almost twice that. But ride it side by side in city traffic, and my bike goes further.

-Crissa

 

[firsttruck]

At 55 mph on level road, 50% range increase (300 wh/mi reduction) due to better aerodynamics of new trailer.

-------------

Tesla Model X LR+, 100 kwh, 5,421 lb (2,459 kg), 350 miles range
2021 Apex Nano 194bhs 22', 4,800lbs, 55mph, 800 wh/mi 108 mi between charge
2018 Airsteam Bambi 22', 4,500lbs, 55mph, 489 wh/mi, 177 mi between charge
Able to go about 50 more miles before having to charge using Airstream Bambi.
50% range increase.

Other vehicle:
2017 Ford F-350 15-17 mpg, 8-10 mpg towing ( 50% loss)
2019 Grand Design Reflection 312BHTS 37ft 10,000lbs trailer

An Airstream and an EV || Tesla Model X Towing an Airstream Bambi
Oct 11, 2020
All Electric Family



Tesla Towing an Airstream || Part 2
Oct 18, 2020
All Electric Family

 

[CappyJax]

At 55 mph on level road, 50% range increase (300 wh/mi reduction) due to better aerodynamics.

-------------

Tesla Model X LR+, 100 kwh, 5,421 lb (2,459 kg), 350 miles range
2021 Apex Nano 194bhs 22', 4,800lbs, 55mph, 800 wh/mi 108 mi between charge
2018 Airsteam Bambi 22', 4,500lbs, 55mph, 489 wh/mi, 177 mi between charge
Able to go about 50 more miles before having to charge using Airstream Bambi.
50% range increase.

Other vehicle:
2017 Ford F-350 15-17 mpg, 8-10 mpg towing ( 50% loss)
2019 Grand Design Reflection 312BHTS 37ft 10,000lbs trailer

An Airstream and an EV || Tesla Model X Towing an Airstream Bambi
Oct 11, 2020
All Electric Family



Tesla Towing an Airstream || Part 2
Oct 18, 2020
All Electric Family

Your “evidence” supports my statement more than yours.

 

[firsttruck]

Your “evidence” supports my statement more than yours.

The new trailer had almost the same weight but much better aerodynamic.

What part supported your prediction?

 

[CappyJax]

The new trailer had almost the same weight but much better aerodynamic.

What part supported your prediction?

"Tesla Model X LR+, 100 kwh, 5,421 lb (2,459 kg), 350 miles range
2021 Apex Nano 194bhs 22', 4,800lbs, 55mph, 800 wh/mi 108 mi between charge"

An increase from 335Wh/mi to 800Wh/mi from a 4,800 pound trailer with a frontal area of 74 sq/ft would mean that a fifth wheel that weighs nearly 3 times as much with a frontal area of 110 sq/ft is going to us a heck of a lot more energy.

 

[firsttruck]

"Tesla Model X LR+, 100 kwh 5,421 lbs (2,459 kg), 350 miles range
2021 Apex Nano 194bhs 22-ft 4,800lbs, 55mph, 800 wh/mi 108 mi between charge"

An increase from 335Wh/mi to 800Wh/mi from a 4,800 pound trailer with a frontal area of 74 sq/ft

Are you saying your spreadsheet predicted that at 55mph the results would be:
335Wh/mi for Tesla Model X 5,421 lb (2,459 kg)
and
800Wh/mi for Tesla Model X LR+ 5,421 lb (2,459 kg) + Apex Nano 194bhs 22-ft 4,800lbs

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