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Front drivetrain (not even optional) potentially affecting the MS-type crumple zone

Front drivetrain (not even optional) potentially affecting the MS-type crumple zone

Granted, some people want all-wheel drive so badly that they ignore safety issues. A traditional concern is a head-on collision driving the engine back into the passenger cabin. Not in a MS, with its superb crumple zone.

After seeing the MX models showing the front drive unit perched up higher than the rear's, I wondered what Tesla was doing to make sure the MS safety design was not lost. Tesla engineers are clever; perhaps they found a way to mitigate this hazard. Anyone know?

And it now seems that a front drivetrain isn't an option anymore. You get it even if you don't want it. We need a convincing statement from Tesla about why a potentially inferior safety design is being forced on customers.

wcalvin | 21 juin 2014
wcalvin | 21 juin 2014
Red Sage ca us | 21 juin 2014

It will still be far lower than a motor in a conventional ICE vehicle. Look closely... The top of the drive unit doesn't even clear the top of the front tires. Assuming those are 21" rims, with 3" high tire sidewalls, the whole front motor assembly is still barely over two feet -- 27" maybe -- off the ground at its highest point. In conventional Crossovers, SUVs, and minivans, the motors are way higher.

The crumple zones will be designed to contain that mass. It is likely that a truly disastrous frontal impact would actually destroy the drive assembly, breaking it down into smaller component parts. None of those would ever enter the passenger compartment. Get good insurance though, because that would definitely mean the car would be 'totaled' as a result of such an accident.

NumberOne | 21 juin 2014

If you look at the open prototype chassis, you will notice that the front motor and invertor is set back a lot further from the front of the vehicle. The open box in the Model S (If you open the frunk this will be obvious) is the location of the front motor. It will pose no hazard to those seated in the front of the car, and will still have a significant crumple zone. The front motor and drive inverter is also significantly smaller than an engine of any size. The picture above also does not snow the solid high strength steel beam in the front of the chassis, which offers significant protection.

I do not mean to be critical of your post, but you asked if they found a way to make it safe for frontal crash events with the motor perched like that. The answer is yes, but you will have to see the production prototypes to be convinced.

wcalvin | 21 juin 2014

Thank you all. Very good points.

lph | 21 juin 2014

Another thing is that the battery pack is enormously strong with that 1/4" thick plate underneath.
its real strength is not just in protecting the battery from debris but also in taking forces along its strong axis (along the length and width of the plate). Additionally the battery pack enclosure likely acts to stabilize from buckling the plate which makes the passenger box immensely strong like no other car I can think of. The crumple zone is important to reduce the G forces in a crash. But just as important is the strong container for the people (as F1 racing discovered a few years back).
It appears that the inverter and motor are at the front of the battery so even if the crumple zone was used up the battery plate would provide a buttress against significant further intrusion.

wcalvin | 21 juin 2014

No, the issue is the front drivetrain detaching to move back atop the battery slab, in the manner of gas engines in small trucks without sedan-like unit construction that crumbles to protect passengers.

I keep seeing that battery slab as analogous to those front-to-back rails in small trucks to which all else is attached. But it doesn't matter in the MS because there is nothing big and heavy to move rearward from the "Microwave" space.

Of course, they might have engineered the front drivetrain to function as part of a crumble zone, working differently from the one in the Model S. Do I gather there hasn't been much discussion of this?

(I normally hang out in the MS forum. But now I am advising an organization considering leasing a MS and later a MX for ferrying people between sites all day. So you will see more of me here.)

gdubcobra1 | 21 juin 2014

Can you do some little research before post statements and comments as if you are an auto engineer? And there isn't a real leasing an MS, it a buy back program. Get a clue.

Brian H | 23 juin 2014

gdub;
There is now a business leasing program. Get ½ a clue.

NetWatchR | 24 juin 2014

As other's have said, the motor and assembly is pretty low and behind the wheels. So there's a lot of "car" to crumple before it gets that far. Second, Just think of how those two things are just opposite of what is in a front ICE. The engine is higher and is the second thing to start getting pushed in your direction.

Now, obviously, things may change as R&D shifts from R to D, but as it is now, they don't have to do anything special to make it safer. The motor's current location and absence of an ICE make it safer by default.