How much extra would you pay for AWD

[Raffy.Roma]

To support what your're saying:

"Torque-Vectoring all wheel drive system monitors vehicle speed, wheel speed, gear position, steering angle, yaw rate, lateral G forces and other inputs, and automatically adds torque to the outside rear wheel in corners to make the car turn quicker."
Torque-Vectoring Awd | awd cars, 4x4 vehicles, 4wd trucks, 4motion, quattro, xDrive, SH-AWD, Haldex, Torsen, wiki - How it works

Notice the torque is applied to outside rear "wheel" not wheels.

You are right. From the picture in the link mentioned by Johan I saw a car where the torque was applied to three wheels (both rear wheels and outside front wheel). That's why I thought that the Torque Vectoring All Wheel Drive System performed what I meant by "active" ESC. Main thing is that when Tesla will design ESC for AWD Model S and AWD Model X the torque will be available to all the wheels when needed.
Anyway I saw once a video with an AWD ICE car on the snow (used as a Demo for ESC on AWD cars) where at slow motion it was possible to see all the 4 wheels stopping and accelerating independently. So I think that what I call "active" ESC already exists.
Second thought is that turning quicker the car in corner is one thing, keeping the correct path while turning is another thing.
In the second case it's very much a matter of Stability rather than of turning quicker. I think that in this case the Torque Vectoring All Wheel Drive System may apply the torque to all the wheels.
That's why in the picture that I mentioned above the torque was applied to three wheels (both rear wheels and outside front wheel).

 

[Boltz]

"I don't see how they could add another motor and inverter for less than $10K, and would not be surprised it it's higher. Maybe they'll downsize the rear motor and inverter since duties will be shared, which would provide some savings, but not much"

Why? Tesla states that the X and the S will be comparable in pricing. If they can make the AWD X for 90,000 they can make the S AWD around the same price. Same skateboard, options, range - the main difference is styling.

 

[vfx]

"I don't see how they could add another motor and inverter for less than $10K, and would not be surprised it it's higher. Maybe they'll downsize the rear motor and inverter since duties will be shared, which would provide some savings, but not much"....

Tesla may develop a shared inverter. They have been doing groundbreaking battery schemes. The real trick would be if the AWD front motor were used in another application. Bluegenlll?

 

[JRP3]

Why? Tesla states that the X and the S will be comparable in pricing. If they can make the AWD X for 90,000 they can make the S AWD around the same price. Same skateboard, options, range - the main difference is styling.

Comparable to what though? If the AWD X is 90K that's 13K more than the standard 85kWh S.

Tesla may develop a shared inverter. They have been doing groundbreaking battery schemes.

Everything I know about AC induction motor control, and everything I've learned from people who know a lot more than I do, tells me that's not possible. Rotor position is crucial in controlling an AC induction motor and two separate motors would never have the exact same rotor position.

 

[Boltz]

From the Tesla website for the X

"WHAT'S NEXT?
We unveiled the Model X Design prototype on February 9, 2012. It represents our current vision for this groundbreaking vehicle. Deliveries will begin in 2014 and priced comparable to a similarly equipped Model S. More details will be announced as production nears.


Here are the vehicle configurations we plan to offer:


Battery Options
Model X will be offered with a 60 or 85 kWh battery.


Drivetrain Options
Model X will be offered with the following drivetrain configurations: 60 or 85 kw"

if it is similarly priced, I am assuming X performance with AWD is comparable to S performance. How will they justify a significant difference in price if they add the AWD option to the S? What will be the discernible difference between a S performance with AWD and an X performance with AWD? The "guts" of the car are identical - so it is just styling - SUV vs Sedan. Where is the cost difference?

 

[Doug_G]

AWD will be an option for the X, not standard. It will cost more. When they eventually add AWD to the Model S that version will also be more expensive.

 

[Boltz]

I'm interested in how they price the X AWD performance it in relation to the performance S. I'm hoping we don't have to wait to long and Elon releases the "variants" soon. I have AWD on both my current vehicles and would love it if they add it to the S as a "reasonably" priced upgrade.

 

[VolkerP]

A 2014 Model S with AWD performance option would qualify as contestant for the 2015 MT COTY :love:

 

[Norbert]

2013 Porsche 911 Carrera 4 and 4S First Drive - Motor Trend

Wait a minute. All-wheel drive accounts for 34 percent of 911 sales worldwide, says 911 product line director August Achleitner. It's nearly 50 percent if you count the 100 percent AWD 911 Turbo. Porsche isn't about to give up that business -- certainly not to the Nissan GT-R.

So is the Carrera 4/4S worth the extra money and the slight degradation in performance from about 110 more pounds?
For an extra $8930 to $9530, you get black rocker panels with an aerodynamic design; 0.04-inch wider tires and 0.9-inch wider rear wheel flares; a red light strip across the rear deck visually connecting the two taillamps; front parking sensor; an AWD system that can shift 100 percent torque to any one wheel, theoretically; and a new torque split indicator on the instrument panel's right bezel. All for about the price of a good, used Subaru over standard RWD Carrera models.

(Of course, this doesn't include an extra motor.)

 

[Robert.Boston]

(Of course, this doesn't include an extra motor.)

True, but it does include a very complex, highly engineered transmission. I'm not an engineer, but to my eye it's simpler to implement true AWD in an EV than an ICE.

 

[JRP3]

Simpler but probably more expensive at this point in time. High power switching electrical components are not cheap, nor I suspect is the copper rotored Tesla motor. An ICE transmission is just steel and aluminum.

 

[Raffy.Roma]

True, but it does include a very complex, highly engineered transmission. I'm not an engineer, but to my eye it's simpler to implement true AWD in an EV than an ICE.

That's right Robert. The electric engines, not having the greater inertia of ICE, integrate much better with the ESC. In fact the answer of the electric engines both on the rear and the front wheels to the commands coming from the ESC is much faster.

- - - Updated - - -

Simpler but probably more expensive at this point in time. High power switching electrical components are not cheap, nor I suspect is the copper rotored Tesla motor. An ICE transmission is just steel and aluminum.

For the time being high power switching electrical components and a further electrical engine maybe more expensive. But they are more efficient. Then it should be considered that on a large scale production they could also become cheaper.

 

[Norbert]

Apart from the question of complexity and/or cost, another difference is that an extra motor also gives more total torque and therefore value.

 

[Raffy.Roma]

Apart from the question of complexity and/or cost, another difference is that an extra motor also gives more total torque and therefore value.

Right. Then another motor makes also the car safer in dangerous situations and this is very important!

 

[vfx]

Simpler but probably more expensive at this point in time. High power switching electrical components are not cheap, nor I suspect is the copper rotored Tesla motor. An ICE transmission is just steel and aluminum.

Along with Raffy's comments I'll point out development costs. Software is much easier to change on the fly than that steel and aluminum Much cheaper to design an electric.

 

[JRP3]

You still have to pay for someone to write the code, and there is a lot of code going into dynamically controlling an electric motor, let alone two of them, and that code has to be rock solid.

 

[tander]

With proper winter tires, how critical is AWD? It's been many years since I've driven in snow.

I've driven AWD for a decade now with just all season tires and never had to use chains or gotten stuck. I'm sure part of it is just having experience driving in snow and knowing your car's limits, but as an avid skier I can't count the number of times I've seen vehicles even with four wheel drive slide off the road or get stuck. Not having AWD is usually my chief reason for not buying a car (still waiting for a awd tdi Passat or Jetta). That said I've never driven a Roadster or S in the snow, so it would be interesting to see a really good winter test of Teslas v. others.

 

[Raffy.Roma]

You still have to pay for someone to write the code, and there is a lot of code going into dynamically controlling an electric motor, let alone two of them, and that code has to be rock solid.

These costs are Research and Development costs. But once the work to develop an AWD electric car is done you can use this work on all AWD electric cars. I think it's worth of it. Eventually these costs will be repaid from people happy of having AWD electric cars.
And I think many people will wish to have AWD electric cars because, for what has been stated above, they are better than conventional AWD ICE cars.

 

[vfx]

You still have to pay for someone to write the code, and there is a lot of code going into dynamically controlling an electric motor, let alone two of them, and that code has to be rock solid.

You are right. Today's Infernal combustion engines have no code in them for anything.

 

[JRP3]

Fair point. I still think AWD is going to be more expensive than many of you are suggesting. I'd love to be wrong of course.