Exterior Design

Hummer EV

With cutting edge EV technology and unique design details, the design team has created a vehicle that is recognisably Hummerish without looking retro

Leading the exterior design team was John P. Mack, current design manager for Chevrolet’s Performance studio. Mack has overseen design for the Camaro programs since 2015 and previously served stints as exterior design director for GMC and as the design director for General Motors’ advanced design studio in Seoul, Korea. He’s no stranger to EVs either; nearly a decade ago he headed up the exterior team for GM’s extended range electric vehicles, which included the Chevrolet Volt and the production version of the Cadillac ELR.  

Mack echoes Zak’s sentiments that the goal was not to resurrect a decade-old design, but to catapult it into the present. “The Hummer name had been asleep for roughly 10 years. So what would the vehicle look like in that absence if it were still going on?” The answer was a design that kept a lot of the DNA from the past, but brought forward into a new aesthetic. “We were really unleashed to come up with something extremely unique, making it a very new technology statement with the EV as the driving force for the new design,” he says. 

The exterior team came up with a list of must-haves based around function, lifestyle, visual cues, and capability. They included:

• Off-road proportions and stance with a wide track and high ground clearance

• Hummer DNA elements including a low turret upper daylight opening, upright windshield, and six-bar front grille that somehow incorporated the electrification strategy

• All visible elements “designed,” such as the skid plates, tow hooks, underbody, wheel liners, and suspension parts

• An open-air removable top with a place for storage inside the vehicle and a roof rack system that enabled accessories 

The compressed timeline is something the HUMMER EV design team mentions repeatedly, and for good reason. Unlike the traditional design process where the bulk of the engineering is done before the project is handed off to the studio, engineers and designers collaborated in tandem. “We had to break the rules outside the normal GM process,” Mack explains. “The architecture of the vehicle was being developed mostly at the same time our design was going. We were modifying as we went; we had scales going on at the same time as we had a full-size going. The full-size was basically capturing the proportions that we wanted, and then we were working with engineering to make sure those proportions were enabled by the platform.” 

Mack remembers they had engineering meetings almost daily on the studio floor. If an issue came up, they resolved it that day. “We didn’t want to do the normal meeting format where we’d say, ‘OK, we’ll get back to you in a week.’ Frankly, it was liberating to have that type of working environment because things got addressed extremely quickly. It was quick but it wasn’t reckless; it was very detailed as well.”

Multiple exterior themes were submitted by designers, including those from GM’s Australia and California studios. “They gave us a good range of options, going from evolutionary to more NASA-inspired, and a lot of them in between,” Mack says, noting that the most future-forward ideas came from California. “All of these themes were really kind of a shotgun approach, but we categorized them in terms of levels of reach.” The team also experimented with sketches of the fastback body styles found on Hummer’s H1 military vehicles. “But it didn’t feel right for what we were trying to do,” Mack admits, “so we ended up with more of a traditional truck bed in the back, but not the flying buttress approach.”

"If an issue came up, they resolved it that day….It was liberating to have that type of working environment because things got addressed extremely quickly."

Although EV platforms generally afford designers more freedom, the team didn’t want to stray too much from the Hummer look and feel. “An electric architecture opens opportunities for design, but for the Hummer, we wanted to maintain that unique silhouette,” Zak explains. “But we could put the windshield pretty much where we wanted to. And it still has large motors, but they go outboard to the corners more, so that was a big enabler since you don’t have a big internal-combustion engine under the hood.”

As a final direction emerged, the exterior team find-tuned the Hummer’s attributes, including short front and rear overhangs and “body-side in, wheels out” proportions to emphasize the vehicle’s width. “The fender forms bulging out from the body side with a very clean body-side aesthetic was something that was from the Hummer of the past, with clean wheel forms and a very turret-like upper,” Mack explains. The team went into full-size clay development on their patio in Warren through multiple reviews during all weather conditions. “No matter what, we had to work through the winter on this,” he says.

"An electric architecture opens opportunities for design, but for the Hummer, we wanted to maintain that unique silhouette"

"An electric architecture opens opportunities for design, but for the Hummer, we wanted to maintain that unique silhouette"

According to Mack, the final theme came from GM’s home studio in Warren, Michigan, whose design telegraphed a proud, confident stance with geometric shapes that define the form vocabulary. In incorporating the Hummer DNA, the 6 vertical bars that comprised Hummer front grilles of the past became the lighting signature and thus the new face of the vehicle. Other design cues include air extractors as a graphic to visually shorten the front overhang, tow hooks integrated into the front fascia, and a steel skid plate that allowed for an off-road approach angle at 45 degrees. The colour scheme on the Edition 1 will be the only option at launch, with a striking white body, high gloss uppers, and lowers with a subtle metallic fleck. Eight-spoke, 18-inch aluminium wheels are accented with “tech bronze,” which is echoed throughout the interior. For daily driving, the vehicle will ride on standard 35-inch tyres but is designed to accommodate 37-inch tyres for even more extreme off-roading.

The HUMMER EV’s bed measures five feet, which Mack says is considered entry-level for any truck in the marketplace today. The Hummer H2 of the past had a very short bed, so the team found ways to increase the utility of the new Hummer without drawing too much attention to the increased length. “We didn’t want it to look like an overt truck. So we graphically took this tail-end graphic wrapped it around the corner to visually shorten the overhang,” he explains. “We wanted these short front and rear overhangs to show that we have great departure and approach angles and to really minimize that long-bed look.” To cap it off, a six-way, multi-function tailgate was created to aid accessibility when loading and hauling. Essentially two tailgates in one, the segments can be raised and lowered in different combinations, and also turn into a step. 

From the side perspective, Mack points out that the lower segments that wrap around the front and the rear also form a protective shell around the vehicle, with the body-color insert that really looks protected from the outer surroundings. “You also have design features like the upper; those are areas that could have been something that was really hard to execute, but we made it look functional. It has a product design sensibility to it.”

Lighting design played a role in not only creating the face of the HUMMER EV, but to showcase state-of-the-art technology.  “The lighting in the front was very unique,” Mack says. “We utilized some of the current tech that’s out there like light cone technology, where we project light through a crystal and essentially it’s lighting up a mechanically-cut detail on the lens that you can see through, and also it projects light forward once the light source is lit.” Mack points out that when the lighting beneath the Hummer graphic is off, you can see right through it. Headlamps feature a subtle stretched H-shape – one of the many “subliminal Easter eggs” that are scattered throughout the vehicle. Tracer lights animate in yellow when the turn signal indicator is on, and in blue while the vehicle is charging, visually indicating the level of charge. Tail lamps are done in a vertically inverted H-shape and are edge-lit. “This is another feature that looks high-end jeweled surfaces,” Mack adds. When off, the tail lamp appears stealth black.

A particular point of pride is the four-piece, removable roof with glass panels that store in the “frunk,” or bonnet compartment. The front panel storage area was designed with bead-foam containers, with a specific slot for each panel, and have tie-down straps for secure storage. The rear drop glass can also be opened for a fully immersive open-air experience. 

The exterior team also worked on less-visible areas often overlooked by the design department. “Every aspect of this vehicle is designed, head to toe,” Mack explains. “The undercarriage, all the details, and some surprise Easter eggs throughout. We took a lot of care in making the underbody look robust as well. It’s going to be scraping rocks, but we wanted to make it look good.” One designer worked specifically on the underbody, control arms, and skid plates. “He was looking at science-fiction weaponry; that really inspired him and he started working with engineering on it. To be honest, we do not typically design parts like the wheel wells. But in this case, we worked hand-in-hand with engineering so every part is well thought out.” 

Similarly, GM Design interior, exterior, and colour and trim departments worked in the same room, which was dedicated exclusively to the Hummer development. “Even the interior was developed in the same studio from the design side, and everything that we were doing they saw,” Mack explains. “They integrated all the surface changes from our exterior movement into theirs as well, so I think it was good for them to see the surface development that we were doing and they echoed some of that same aesthetic into the interior. We also had colour and trim come in and propose different materials and textures as were developing the interior and the exterior at the same time. And from that collaboration aspect it worked really well.”

Unlike some studios, there was no mandate for designers on what would be done digitally versus via traditional methods. “It was up to us how we wanted to handle it; everyone works differently,” Mack tells us. “Initially we milled out rough proportions to the package for the scales, and then the scales were done manually with the clay and early sculpting, but we tried keeping the full size up to the current dimensions and specs. And math development was happening at the same, time so we’d also do digital reviews as well, but it was more to see the proportions in the real world criteria, and how it affected our themes. So it was a little bit of both (digital and analogue), and we all worked to what we felt comfortable with. Some guys work in digital sketching, and some actually build Surface as a sketch tool, and some just use the digital tools they have available. There’s nothing specified, and I think that’s a good thing.”

"One designer was looking at science-fiction weaponry; that really inspired him and he started working with engineering on it"

"One designer was looking at science-fiction weaponry; that really inspired him and he started working with engineering on it"

But when it comes to the development cycle, some new processes have emerged. The collaborative, rapid workflow necessitated by HUMMER EV has sparked change for subsequent GM design projects, and is something the company is experimenting with now. “We’re working on setting a newer standard for timing with programs going forward,” Mack reveals.

Professional Profile:
Name: Brian Smith
Role: Director of design, Cadillac exteriors
Nationality: American
Location: Warren, Michigan, USA
Education: University of Cincinnati, USA 

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