Single Motor - "Positive Traction?"

[JBee]

Any guesses if the single motor variant will have some form of positive traction, torque converter where in spite of a single motor, torque can be applied to more than one wheel? I've never seen comments about how this works in a single motor Tesla.

I would be surprised if Tesla removes the differential lock from the RWD motor setup.

With a mechanical differential lock both rear wheels will be locked together by a mechanical clutch between the two rear driveshafts. This will greatly improve traction on loose surfaces, but it also limits how well the CT will steer, and shouldn't be used on high traction surfaces at all, as this can damage the drivetrain.

In comparison, the traction control system uses both the motor (at high frequency switching) and the brakes (low frequency) to modulate wheel rpm to match available traction. It does this by comparing the rear wheel rpm to the front wheels, and commanded steering input.

With this control method it is possible to do yaw control on the CT, like with ESP on convectional ICE vehicles, which means it would act like torque vectoring and try to steer in the wanted direction by using different wheel rpms on either side. However, unlike the CB with two independent rear motors that can control each wheel RPM directly, this effect can only be achieved via the brake system on a single motor RWD CT and is less responsive.

Also traction control using brakes uses more energy and as such also can reduce power output, even though in some situations, like on sand, you actually want wheel slip to propel more sand under the wheels. That is why most offroad vehicles have different traction control profiles for different driving surfaces. On ice for example you want the traction control more sensitive, so you don't go sideways, and as such using the differential lock at over 1-2MPH is not recommended.

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[HaulingAss]

I'm not quite sure how removing a single motor will bring the cost down though. Surely they wouldn't start producing a different battery pack, right?

Anyone know the replacement cost of the rear motor?

The single motor is expected to have a reduced range of 250 or so miles. That means it will likely have a smaller battery to reach a more affordable price point. The savings will be multi-fold:

1) One less motor to make
2) One less inverter to make
3) One less differential to make
4) one less drive unit to install
5) Less high voltage wiring
6) Less batteries to produce
7) Lighter weight equals less expensive tires

It's possible the entry level Cybertruck will come with a fixed suspension too. That would remove a huge amount of expense in the variable dampers, the air compressor and air tank, and installation of air lines to each corner.

 

[REM]

The single motor is expected to have a reduced range of 250 or so miles. That means it will likely have a smaller battery to reach a more affordable price point. The savings will be multi-fold:

1) One less motor to make
2) One less inverter to make
3) One less differential to make
4) one less drive unit to install
5) Less high voltage wiring
6) Less batteries to produce
7) Lighter weight equals less expensive tires

It's possible the entry level Cybertruck will come with a fixed suspension too. That would remove a huge amount of expense in the variable dampers, the air compressor and air tank, and installation of air lines to each corner.

I suppose, but to remove all of that from this masterpiece of a truck? Bleh-sphemy! lol

 

[JBee]

Might as well delete RWS as well while you are at it. Won't happen though.

By the time RWD comes out, the battery pack will likely be cheaper than they budgeted for in 2019.

Deleting 20kWh of pack is worth a mere $2000... worst trade off ever IMHO.

 

[ABILISK]

It's possible the entry level Cybertruck will come with a fixed suspension too. That would remove a huge amount of expense in the variable dampers, the air compressor and air tank, and installation of air lines to each corner.

C’mon now, Tesla doesn’t work backwards. RWD will just be slower and have less range. Everything else will be all CT.

 

[ABILISK]

I doubt we ever see a single motor variant, to be honest.

I’ll bet you a Tesla share we do

 

[HaulingAss]

I suppose, but to remove all of that from this masterpiece of a truck? Bleh-sphemy! lol

I wouldn't get one, but ever since Tesla announced the pricing we have had to endure a lot of people clamoring for a basic, low priced truck, without superior off-road capability or acceleration performance. Just a simple, durable truck that is tough and reliable. That's what a lot of people want.

 

[HaulingAss]

I’ll bet you a Tesla share we do

Before or after they split again?

 

[ABILISK]

Before or after they split again?

I’ll give ya before lol

 

[ABILISK]

I wouldn't get one, but ever since Tesla announced the pricing we have had to endure a lot of people clamoring for a basic, low priced truck, without superior off-road capability or acceleration performance. Just a simple, durable truck that is tough and reliable. That's what a lot of people want.

People are gonna have to deal with the fact that trucks cost $60K now. You can get a Maverick or a Colorado in the high 30s/low 40s but if you want a real truck it’s $60K in 2025. Tesla won’t sell you a half-assed truck. Even the RWD will be the most mind-blowing thing most people have ever had the pleasure of driving.

 

[HaulingAss]

People are gonna have to deal with the fact that trucks cost $60K now. You can get a Maverick or a Colorado in the high 30s/low 40s but if you want a real truck it’s $60K in 2025. Tesla won’t sell you a half-assed truck. Even the RWD will be the most mind-blowing thing most people have ever had the pleasure of driving.

True, A single motor Cybertruck won't have that aggravating quality of RWD ICE pickups of being too light in back when unloaded to get traction or handle decently, because the battery and rear drive unit (and lack of a heavy engine/transmission up front) will give good weight distribution from front to rear.

 

[Deleted member 17810]

Might as well delete RWS as well while you are at it. Won't happen though.

By the time RWD comes out, the battery pack will likely be cheaper than they budgeted for in 2019.

Deleting 20kWh of pack is worth a mere $2000... worst trade off ever IMHO.

There's no way tesla is making a different slightly smaller battery pack.

They'll just software lock it if they want to squeeze more money out of it, like they've always done.

 

[Willinak]

So, why would the single motor have less range?

 

[mongo]

So, why would the single motor have less range?

Smaller pack

 

[Willinak]

Smaller pack

I understand that, however that’s not very good marketing, imho. I thought the current holy grail for range is 300+ miles.

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