GMC Granite concept's production fate hinges on door feasibility

[Sal Collaziano]

Filed under: Concept Cars, Crossover, Hatchback, GMC

GMC Granite concept - Click above for high-res image gallery​

The compact-sized Granite crossover concept shown by GMC at the Detroit Auto Show proved extremely popular with attendees, and the "Professional Grade" division at GM really wants to put it in production. According to new GMC product marketing director, Lisa Hutchinson, the main stumbling block right now is figuring out how to build the doors. The Granite featured the same rear hinged back doors that are commonly used on concepts to show off the interior.

The goal is to retain the door design for production to maximize access to the rear seat. However, the doors will have to be engineered so that the car can pass side impact safety requirements, an extremely difficult task without a fixed B-pillar, especially on such a small vehicle. The engineering feat has been managed before, as seen on the Mazda RX-8 and Honda Element, but the rear doors on the concept Granite would appear to require a larger opening than the demi-doors on either of the two Japanese offerings, making engineering significantly tougher. Of course, GM could still build the model with a hidden pillar à la Opel's 2011 Meriva, but that might compromise some of its appeal, or its utility if they can manage to build it with the concept's trick folding seats. In any case, GMC itself has shown that it can build rear-hinged doors, as it already has the Sierra extended-cab pickup, but that vehicle's body-on-frame architecture and less weight-sensitive construction could make that an easier manufacturing feat.

At this point, the fate of the Granite remains up in the air.


Gallery: GMC Granite Concept







GMC Granite concept's production fate hinges on door feasibility originally appeared on Autoblog on Thu, 10 Jun 2010 11:31:00 EST. Please see our terms for use of feeds.


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[Molson02536]

GMC Granite Concept

As for the Safety Issue with the door's, the leading edge of doth front and rear doors can be reinforced by using a higher grade sheet metal or having a filler between the sheet metal in a egg carton design to give it the rigidity of a pillar of not more since there is the front and the rear doors that attach to the frame.

The only other concern is the way the weather strips and locking system is to lock the door close firmly to avoid any wind noise and water leaks. That may be achieved by having the lock system, lock from the top and bottom of the door frame to the body frame with the striker having an angle to pull the door in tight in to the frame of the Granite with a ability for adjustments throughout it's life. Not like the issues with the S10, Sonoma, and the full size pick up trucks GM has out with the wind noise and rattles from misaligned doors.

I hope this Granite makes it way out in the public world and not just in the concept after the bugs has been worked out.

Harvey T
Molson02536

 

[CZTiger]

I see this having the same problems as most third doors overtime. Once the doors get misaligned it will be a hassle for someone to ever get them properly realigned in the future without taking it to an official dealership, and who's to say that it will ever open and close like factory.