Why The Long Wait, Tesla Model X?

The Tesla Model X has been on a zealous multitude of wish lists ever since the first prototype was revealed in early 2012, thus sparking cold feet and disappointed consumers when the all-electric crossover was delayed, multiple times. While quite speculative, Green Car Reports has compiled a list of the three biggest (likely) hindrances to the electric utility’s release:

     1. Range Ratings

Green Car Reports reminds us that the Tesla Model X, well, it ain’t no Model S; it has a larger frontal area, contributing readily to more drag, and likely much more weight to haul around. All of that likely contributes to some tough challenges with regard to squeezing more driving range out of the thing.

The manufacturer had planned on equipping the Tesla Model X with side rearview cameras instead of mirrors, to reduce the cross-section and remove a major contributor to drag, but NHTSA hasn’t approved such equipment yet, and Tesla Motors isn’t likely to get the green light anytime soon. As-is, a range of under 200 miles would be likely with the automaker’s 60 kWh battery pack, which simply isn’t sufficient for a $70,000+ vehicle.

     2. Falcon Doors – Structural Issues

The vertically-inclined falcon doors of the Tesla Model X likely contribute to some number of complications for development – go figure. But they are the focal point of the design, in a lot of ways, not to mention astonishingly practical in theory. Green Car Reports states that their sources assure them that weather sealing issues have been resolved. It’s the other two complications – crash integrity, and hinge-mounting – that probably demand still more attention.

Because the falcon doors will hinge along a narrow load path along the roof of the vehicle, it’s imperative that the doors have some pretty tricky structural integration going on underneath the skin, so that when closed, they can interlock with the rest of the vehicle’s crash structure. Designing such a structure is challenging in itself, but it could also contribute to more intrusion into the cabin, and increased door mass.

And then, there is the difficulty of hinge-mounting. Because the doors will quite likely be hefty from their required crash structure, and mounted to such a narrow, aluminum roof beam, they are likely to contribute to roof warping over time. One of Green Car Reports’ sources suggests that the hinge mountings for the falcon doors may resort to an expensive titanium alloy, more suited to the concentrated stresses than aluminum.

     3. Towing Capabilities

It was confirmed some time ago that the Tesla Model X would be the first all-electric vehicle with towing capabilities, but that in itself presents engineering challenges. According to Green Car Reports, running the electric drive motors at peak output (or close to) for sustained periods causes a lot of possibly damaging heat buildup. The Tesla Model X will benefit from having two drive motors to share the load, but still, if the crossover is to have any appreciable amount of towing capability at all, cooling the motors will be a concern.

Rumor has it that as a result, Tesla Motors may be testing an active refrigerant-based motor cooling system – rather than the passive glycol-based system in use on the Model S.

Suffice it to say that, given the immensity and breadth of the alleged engineering humps, still another Tesla Model X delay is not out of the question.

Aaron Birch is an automotive enthusiast and writer/filmmaker from Detroit, MI. As a rule, he only buys cars older than himself.

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