General Motors deemed it a “moonshot”, and those working on the newest GMC model dubbed it Project Obtainium. We know it as the 2022 GMC Hummer EV and the freshly debuted pickup includes several interesting tech highlights beyond its wild claim of 11,500 lb-ft of torque that’s been much ballyhooed. There’s a lot to dig into on this EV off-roader, but let’s start by dissecting that torque number before we check out the truck’s trick Extract mode, neat CrabWalk feature, and more.
2022 GMC Hummer EV: Put a Torque in It
Let’s start off with that marquis number: 11,500 lb-ft of torque. That is the combined total torque being applied to the wheels, not at the output shafts of the Hummer EV’s three permanent-magnet motors. (Initially, all Hummer EVs will have one front and two rear motors.) GMC is still being coy about the exact power and torque numbers of the individual motors, but chief engineer Al Oppenheiser pegged the individual motor torque outputs at “between 380 and 400 lb-ft,” adding that after multiplying the motor torque by the 13.4:1 front and 10.1:1 rear single-speed transfer-gear ratios, the number actually comes out to well over 11,500 lb-ft (front output, however, must be limited to prevent wheel spin). If each motor produced 380 lb-ft, that would multiply out to 12,768 lb-ft total to the wheels. Torque limiting the front to 340 lb-ft, and the two rear motors to 350 at launch would pencil out to 11,626 lb-ft at the wheels.
2022 GMC Hummer EV: EV Torque Vs. Duramax Diesel Twist
The Hummer EV’s torquiest combustion sibling is the Sierra 4×4 Duramax pickup, which includes a 10-speed automatic transmission. With its 4.70:1 first gear, 3.24:1 axle ratio, and a torque converter multiplication factor conservatively estimated at 1.85:1 when “stalled” at 0 mph, the Duramax diesel’s 460 lb-ft of peak torque (available from 1,500-3,000 rpm) pencils out to almost 13,000 lb-ft. Of course, that torque-converter multiplication disappears when the converter locks up, trimming total wheel torque to just under 7,000 lb-ft. By contrast, Oppenheiser shared that the Hummer EV sustains peak wheel torque from 0 to 40 mph. Presuming you equip your Sierra Duramax with the X31 Off-Road package to get the two-speed transfer case, you could engage low-range and gain a further 2.72:1 multiplication. That would give you nearly 19,000 lb-ft at the wheels, all along the Duramax’s broad peak-torque plateau. That said, using low-range would rev the bejeebers out of the Sierra’s diesel engine at 40 mph where the Hummer EV’s torque starts to drop off.
2022 GMC Hummer EV: Horsepowerin’ Around
Here again, GMC is only talking in round numbers: 1,000 hp total, measured at the three motor shafts. With more multiplication in the front and a desire to be able to do more torque vectoring at the rear, we’re guessing power and torque ratings will be slightly lower for the front motor than for the two rear motors. Figure somewhere between 330/335/335 and 300/350/350.
See all 30 photos
2022 GMC Hummer EV: WTF Mode
However the power gets divided among the three motors, GMC notes the Hummer EV accelerates 60 mph in about four seconds in its default start-up driving mode. But you can shave a second off that number by engaging WTF mode (that’s Watts To Freedom—this is a family truck!). Selecting this mode initiates a procedure of conditioning the battery and power control electronics, lowering the suspension to near access mode, and building excitement in the cabin with sound effects, graphics, and rumbling from the haptic seat to simulate the excitement that builds as a roller coaster prepares for its first death-defying drop. Once conditioned, press the accelerator and brake simultaneously, release the brake, and enjoy the g-forces.
2022 GMC Hummer EV: Suspension of Disbelief
The Hummer EV’s fully independent suspension consists of “short/long-arm” geometry, which is good for 13 inches of wheel travel at the front and rear, plus air springs and continuously adjustable adaptive dampers at all four corners (none of the suspension bits wear branding from any of the independent off-road shock or suspension suppliers). The Extreme Off-Road package, standard on all Hummer EV Edition 1 models, includes 18-inch wheels wearing 35-inch diameter (305/70R18) Goodyear Wrangler All Territory MT tires. Sufficient clearance is provided to upgrade to 37-inch tires, though. The package also includes steel underbody armor, rock rails, and an 18-camera Virtual Spotter package that includes four underbody cameras—two front and two rear, with self-cleaning capability—to monitor what the tires are encountering. Extract mode helps the Hummer EV clear an obstacle if it becomes high centered by extending the wheels an extra four inches above Terrain mode (to full droop). This feature will become standard in 2023 and will be retrofittable to 2022 models via a software update at no charge. On its 35-inch tires with the suspension set to Terrain mode, the Hummer EV’s approach and departure angles are 44 and 34 degrees, respectively, and the truck can ford 2.5 feet of water. Extract mode increases the approach angle to 50 degrees, but speeds are extremely limited in this setting because there is no available rebound travel.
See all 30 photos
2022 GMC Hummer EV: CrabWalk Diagonal Drive
Another segment exclusive is four-wheel steering that permits up to 10 degrees of rear-wheel steering—well up from the 3-4 degrees most such systems allow. At low speeds, 10 degrees of steering in the opposite direction of the front wheels tightens the truck’s turning circle to a sedan-like 37.1 feet. Smaller rear-steering angles in the same direction as the front tires provide smoother lane changes at highway speeds. Steering up to the full 10 degrees in the same direction at very low speeds permits a diagonal driving direction and can help the Hummer EV clear off-road obstacles.
Source: Read Full Article