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Discussion Starter · #1 · (Edited)
I just noticed something that I don't think anyone has picked up on during the Detroit Auto show or anywhere else really.

GM changed out the lower Grill of the truck. I'm really surprised I didn't see anyone mention this.

(Reveal)
Tire Wheel Vehicle Car Automotive tire

(Detroit During Press Day)
Wheel Tire Car Vehicle Grille
 

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Discussion Starter · #3 · (Edited)
To add to this.... I actually just looked at a recording I did at the show during the public show, and it's different from what we saw in Press Day videos... The Press Truck had a larger blacked out grill and different tires.

Edit 2: Made a few edits to clarify a few things.
 

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To add to this actually.... I actually just looked at a recording I did at the show and it's the same as the original Vehicle on the Floor during Public days BUT DURING PRESS DAYS IT WAS COMPLETELY DIFFERENT.

Edit: Even the Wheels were different!
Its possible they have discovered the need for more cooling system surface area, I have noticed my Hummer with the clear roof panels, on a hot day, and after DC charging, has trouble keeping the interior cool. I have tried to figure out if this is related to the HVAC system, or the solar radiation that gets through the roof panels? My recommendation to people like @azbill living in AZ or other hot areas, avoid those clear roof panels a lot of heat comes in through those, much more than our Audi, or Tesla which both have large glass roofs (heavily tinted).
 

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Its possible they have discovered the need for more cooling system surface area, I have noticed my Hummer with the clear roof panels, on a hot day, and after DC charging, has trouble keeping the interior cool. I have tried to figure out if this is related to the HVAC system, or the solar radiation that gets through the roof panels? My recommendation to people like @azbill living in AZ or other hot areas, avoid those clear roof panels a lot of heat comes in through those, much more than our Audi, or Tesla which both have large glass roofs (heavily tinted).
I have no intent of getting the clear panels. I bought a clip on shade for my Mach E roof and keep it on all summer.
 

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Its possible they have discovered the need for more cooling system surface area, I have noticed my Hummer with the clear roof panels, on a hot day, and after DC charging, has trouble keeping the interior cool. I have tried to figure out if this is related to the HVAC system, or the solar radiation that gets through the roof panels? My recommendation to people like @azbill living in AZ or other hot areas, avoid those clear roof panels a lot of heat comes in through those, much more than our Audi, or Tesla which both have large glass roofs (heavily tinted).
This larger patterned front panel also could be updated aero decision. Some recent aero studies have shown that a full-patterned type fixed panel in the front stagnation area actually creates less drag than a smooth panel. It "trips" the boundary layer and improves attached air flow, something similar to the golf ball dimple effect. Also, I think Audi dimpled the e-tron's bottom panels for a similar effect. I believe all of GM's new Ultium-based EVs have some sort of patterning on their large front grille panels, usually styled in the specific brand's design language.

Also, most current-generation EVs now pull all their TMS air flow from a narrow long grille just above the bottom-front air dam. This grille will have motorized active shutters behind it to throttle or close off the opening as dictated by the TMS logic. This is an aerodynamically-ideal location to put it, as then the TMS, when active, captures some of the air that would otherwise flow under the vehicle and increase drag. Zooming in on that image, there appears to be some openings in that area on either side of the front license plate. @Nebula1701 , did you happen to notice which "grilles" actually were air grilles which were "fake"?
 

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I think it was always the same truck at NAIAS? NAIAS might have been pre-production instead of prototype like they had at Chicago in Feb.
Nevermind, I see what you're saying from some videos. Press event at NAIAS had the same one they had in chicago. Guessing it's more finished or something.

NAIAS
Chicago
 

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Its possible they have discovered the need for more cooling system surface area, I have noticed my Hummer with the clear roof panels, on a hot day, and after DC charging, has trouble keeping the interior cool. I have tried to figure out if this is related to the HVAC system, or the solar radiation that gets through the roof panels? My recommendation to people like @azbill living in AZ or other hot areas, avoid those clear roof panels a lot of heat comes in through those, much more than our Audi, or Tesla which both have large glass roofs (heavily tinted).
That is probably related to the DC charging. The AC system shifts almost all of the refrigerant to the glycol chiller to bring the pack's cell temperatures back down to a more normal level. The pack requires about 15-20 kW of cooling just for the pack, which is over 5 tons when thinking about typical household cooling. And you have about 2,000 lb of cell thermal mass, which will take some time to get cooled down. Now add a glass roof on a hot day for the cabin HVAC. That's about 3.5 tons of cooling. You'd need a large commercial AC type system to make all that work at the same time, which is too much even for a Hummer-sized vehicle to handle. When you get that worst-case scenario, quickly duck into the mini-mart and hang out a while sipping Slurpee's.
 

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Discussion Starter · #18 ·
@Nebula1701 , did you happen to notice which "grilles" actually were air grilles which were "fake"?
I watched several press day videos, It appears everything I outlined in Red here is open to air, and orange is hard to tell but it may also be open. The orange area was open on the older grill.
Vehicle Land vehicle Car Grille Automotive lighting
 

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I watched several press day videos, It appears everything I outlined in Red here is open to air, and orange is hard to tell but it may also be open. The orange area was open on the older grill.
View attachment 3205
They def made some changes, have to get a close up look to see what those mean... I do not think any EV needs as much air as you are showing through the front, hummer takes some air from underneath. Silverado E may have the ability to hold DC charge rate longer, and I saw Andy Oury post to InsideEV that Silverado will be a "Charging Beast", so there may be some system updates from Hummer learnings.
 
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