In-wheel motor

[ac65mkna]

Elon,
The wheel hubs have a lot of spare room. Why not go with the Protean Electric in-wheel motors? They each pack 75HP or could be built to a rating of 100HP each.
This would generate enormous net space in the car.
The unsprung weight issue is not a problem, as documented by Lotus.
Talk to Brabus in Germany, they have lots of know-how about this solution.
Best
Michael

 

[Zextraterrestrial]

..that is less total power than the 1 motor of the S?
unsprung weight not an issue? With lighter wheels on the S it feels much better, I can't imagine adding to the weight of the wheels. It would feel horrible. Torque steering could be nice and awd of 4 motors awesome but I think it isn't a 'good' idea for the S (+ the car has enormous net space as it is)

sorry to attack the idea. The 4 motor Benz is pretty amazing but I think it has a bit more power? (740hp)

 

[pgiralt]

Unless you keep the S drivetrain for the rear and use in-wheel motors for the front. An "extra" 150-200 HP over the S would be pretty impressive.

 

[AudubonB]

I also believe the inefficiencies and the probably horrific undesirable gyroscopic effects of heavy wheels make this option attractive only to such (very, very interesting in their own right - right, Bonnie?!? ) vehicles as a CAT 797. As in: http://autopro1.vcmedia.vn/tPrccccccccccccTQFD4hEqysB4PXe/Image/2013/09/Caterpillar-797-56e1a.jpg

 

[TD1]

Martin Eberhard said in a talk that small motors in EVs are actually more inefficient than bigger ones, there is a sweetspot.
But even if this is solved somehow, I think this option will be reserved for the next Model S/X in around 7-8years if we are lucky.

 

[Lloyd]

Also I believe I read that their motors use rare earth metals.

 

[strider]

Since when is unsprung weight not an issue? Granted I'm a motorcycle guy but I can promise you that lighter wheels make a huge performance difference.

 

[captain_zap]

I'm wondering about the high voltage power cables and control bus that has to get from chassis to the motor hanging on the end of the suspension. This would have to be a very flexible cable routed in a very tough non-conductive sheath. Could be a maintenance problem.

 

[hcsharp]

Tesla already considered this, and another company made a Mini with 4 motors in the wheels around 2006 or 7 I think. I can't find a link right now but they said it had 600 hp. They removed the brakes completely to make more room for the motors. When somebody questioned them about no brakes, they just said they had enough torque to lock the wheels at any speed on any surface, with redundant circuitry to make it failsafe.

 

[scottf200]

Tesla already considered this, and another company made a Mini with 4 motors in the wheels around 2006 or 7 I think. I can't find a link right now but they said it had 600 hp. They removed the brakes completely to make more room for the motors. When somebody questioned them about no brakes, they just said they had enough torque to lock the wheels at any speed on any surface, with redundant circuitry to make it failsafe.

PML Builds 640hp Electric MINI

http://www.worldcarfans.com/10607246585/pml-builds-640hp-electric-mini

While all the world's most famous motoring names look on, a British company, PML, has chosen the UK's most prestigious motor show as the venue to strip away all the misconceptions surrounding electric/hybrid vehicles and to showcase a truly awesome car. Featuring four revolutionary electric wheels, the standard BMW Mini One you can see on Stand 270 is predicted to have a top speed approaching 150mph and to out-accelerate a Porsche 911 Carrera from 0-60mph. Brake horsepower is a stunning 160bhp per wheel - 640bhp in total.[FONT=Arial, sans-serif]The car, dubbed the Mini QED, has been designed to run for four hours of combined urban/extra urban driving, powered only by a battery and bank of ultra capacitors. For longer journeys at higher speeds, a small conventional internal combustion engine (ICE) is used to re-charge the battery. In this hybrid mode, fuel economies of up to 80mpg can be achieved.

[/FONT]