HUMMER EV: BEST OFF-ROAD BEAST
GM’s designers are planning to drive this heavy-duty truck on the Rubicon Trail and on some of Moab’s toughest trails including Hell’s Revenge. Let’s look at what they built to see if they can really do it.
This started as just another electric truck project at GM. But when the designers started hankering for some serious off-road chops, somebody said, “Let’s build a new Humvee”. And what we’re seeing now is military heritage applied to an electric rock crawling, desert running beast that couldn’t be built using traditional methods.
There are some marketing distortions surrounding the Hummer EV and EV trucks in general and we’ll clear the muddy marketing waters as they come up, and the first one is the 11,500 lb ft of torque. This is wheel torque, not motor torque and there’s quite a bit of difference. Watch our motor vs wheel torque video called Motor Torque vs Wheel Torque. If we do the math using the gear reduction ratios of 13.3:1 in the front motor, and 10.5:1 in the two rear motors, we get a total motor torque of roughly 1,000 lb ft, the kind of torque you get in the new heavy-duty diesel trucks, which is a very solid number. My 2011 6.6L Duramax has about 780 lb ft of torque and it pulls like a freight train, never mind the new Chevy 3500HD, which effortlessly yanked around a 15,875 kg (35,000 lb) trailer.
The 1,000 horsepower looks to be on the money. Three engines, two in the back and one in the front are rated at 250kW of peak power. Since there are three of them that totals 750 kW. This translates into roughly 1000 hp.
And that’s how you get from zero to 100 kph (62 mph) in three seconds using Watts to Freedom, one of five selectable drive modes. Watts to Freedom has all kinds of digital theatrics like a countdown, in-dash graphics, music, and a base rumble for an amusement park like
ride as you virtually teleport to 100 kph. There is also Adrenalin mode, which doesn’t have all the in-cabin special effects and takes one whole second longer to reach 100.
These are, dare I say, ‘typical’ electric vehicle numbers. They’re not all that special for EV trucks, none of which are in production yet. But the numbers are impressive for a truck. The Ford Raptor is a benchmark off-road performance truck and it takes 6.6 seconds to get to 100 kph.
Blinding acceleration aside, let’s look at the off-road attributes that make the Hummer EV really stand out. This is GM’s halo supertruck
that is going up against the Tesla Cybertruck, Rivian RT1, and other gas-powered performance off-road trucks like the Ford Raptor and Ram TRX.
GM says the truck is e4WD, which isn’t exactly what you expect. There is no low speed transfer case because electric motors have incredible instantaneous torque. The Hummer EV holds its peak torque through a wider speed range (up to 60 kph (40mph)) than diesel engines. The other thing is you cannot select rear wheel drive only, so it really is an AWD vehicle. When we asked GM they said, ‘AWD - We call it e4WD. We don't run RWD only for a combination of reasons - efficiency, controls strategy, etc.’ For now, the ‘e4WD’ label is just marketing.
When it comes to rock crawling it has a max approach angle of 49.7 degrees, max breakover angle of 32.2 degrees, max departure angle of 38.4 degrees and a max ground clearance of 15.9 inches (404 mm). We say ‘max’ over and over because the truck has a four corner, independent adaptive air suspension system that can raise the truck 15 cm from its standard height in ‘Extract’ mode to help you clear obstacles. It will also take you to a very respectable water fording depth of 813 mm (32 in). You won’t want to drive around in extract mode though as it is speed limited and there isn’t any wheel travel at that height, but in Standard or Terrain mode you will get 330 mm (13 in) of wheel travel.
Since we’re talking about the suspension, it will also lower by 50.8 mm (2 in) to make it easier to get in and out of the truck, improve aerodynamics, and it is used during high speed acceleration in Watts to Freedom or Adrenalin mode to lower the centre of gravity and make the truck more stable.
35-inch tires are standard but in keeping