Model S Test Mule?

Did you get a picture?

 

I bet it was for autonomous driving tests. Pictures would help with the guessing game.

 

We need photos!

 

Standard looking encoders on the wheels. Stop button is curious although I guess they'd have it there for safety even if this is just an AWD mule and not self-piloting.

They could also be testing active cruise control/collision detection...but those comments imply otherwise I suppose.

 

The thing on the roof throws me. External battery pack? That wire going down the A-pillar might be large enough, and might run into the frunk's microwave area where they had considered putting additional batteries... might be battery access terminals up there.

There also appears to be a keyed emergency shutoff switch on the dash.

The wheel sensors might be useful for power/speed measurements. I wonder if you've stumbled across a higher power (120kWh?) AWD test mule.

Edit: Nope, the wire on the pillar runs to the wheel sensors. No idea what that is on the roof, then.

 

I wonder if it is ballast weight on the roof rack, possibly to simulate increased center of gravity for Model X (along with whatever was mounted in back seats).
They could be evaluating driving dynamics of the AWD system.

Edit: Also looks like the fender lining has been removed, at least for the rear right wheel (third photo)

 

Looks a WHOLE lot like an autonomous driving test bed...emergency red stop button would be the biggest clue (take over manual control), with the large box top containing myriad sensors and the "gas tank" in the back likely a beefy server. Wheel dynamics can be tested in a more controlled track envrionment...

 

Were there any wires going in to the metal box on top?

 

It looks like what is attached to each wheel is a wheel torque sensor. My money is on this being an AWD mule of some sort thought it looks like these are used to calibrate braking systems as well...

Wheel Torque Transducer Instrumentation Assembly | Michigan Scientific Corporation

 

This sounds most plausible to me. It's a Model X mule, the roof rack being their to simulate weight for both range testing and dynamics... But of course who knows really ;-) Exciting whichever way!

 

Maybe they are trying to simulate the driving characteristics of the Model X for some reason (more top heavy?)

 

FWIW..

A while back I saw a Test-mule from Mercedes for autonomic driving. It was a bit of a giggle because our daughters connected with a child in the Mercedes (S-Class) and noticed the driver not holding the wheel. He and his son(?) were goofing around, pretending to our girls they were trapped in the car which was clearly driving without driver input.

Anyway, it had cameras everywhere. Bits, bobs and stuff looking out of all the windows. I'm guessing a combo of camera and radar. This car doesn't show anything. I'm inclined to think this has something to do with driving dynamics as stated before..

 

I agree that those are wheel torque, speed and position sensors wrapped into one and that you have spotted the (we are not doing) MS AWD test mule. Until certified, Tesla is probably required to have a big red panic button when working on driveline modifications which further bolsters the idea of their being another motor up front. The box is probably a battery to power that motor independently so as to not have to deal with traction battery peak current usage while exploring the limits of four wheel two motor traction events on dry tarmac.

Awesome find and thank you very much for posting pics

 

for anyone counting at home this theory gets my vote.

 

There are better places to hide an additional battery pack that would not impact the weight distribution and aerodynamics of the MS. I'm putting my vote in the Model X drivetrain prototype camp. YAY!!! Make it so.

No indication of any autonomous driving hardware visible to me.

Edit:
The more I look at this the more I imagine Dr. Brown driving it. I don't know why....but I think when this thing gets up to 88mph we'll see some serious....