GMC's Hummer EV will be powerful, but likely not that powerful.
GMCThe GMC Hummer EV won't officially launch until fall 2021, but it's already throwing down some impressive numbers -- most notably, 1,000 horsepower and a whopping 11,500 pound-feet of torque. Thing is, that second number isn't necessarily an accurate representation.
It all comes down to what specification you use. GMC's massive number appears to correspond to wheel torque, which is traditional motor torque multiplied through the transmission's drive ratio. Jason Fenske from Engineering Explained has a great video that spells out the difference , a piece he published following Tesla's claim that the Roadster 2.0 will produce more than 7,000 lb-ft of torque. Fenske used a Dodge Challenger SRT Demon as an example. That model produces 972 Newton-meters of engine torque (770 lb-ft). However, multiplied through its gear ratios, you get 14,000 Nm of wheel torque (10,325 lb-ft) in first gear.
"Most EVs have a final drive reduction ratio of about 8:1 (Tesla Model X is 8.28:1, for example)," Sam Abuelsamid, principal analyst at Navigant Research , told me. "With 11,500 lb-ft and 8:1, that would translate to motor torque of a bit over 1,400 lb-ft, which sounds right with 1,000 hp. [Chevy's] Bolt has a final drive of 7.05:1, while [Tesla's] Model 3 is 9:1, so 8:1 is a reasonable guess until we know more about the Hummer."
When I asked a GMC spokesperson to clarify, I was simply told the final, SAE-specific number would be released closer to the truck's on-sale date, and that the 11,500 lb-ft spec is what the company is sticking with for now. GMC also said the Hummer EV will be able to accelerate to 60 mph in 3 seconds. The truck will be produced at General Motors' Detroit-Hamtramck plant, which is being retooled to only produce electric vehicles .
2022 GMC Hummer EV is a 1,000-hp supertruck that moves like a crab
See all photos
I recently experienced this torque disparity firsthand. While testing an electric BMW prototype in Germany last summer, an engineer told me the modified 5 Series sedan was producing "around 10,000 Nm on the axles," which equates to 7,357 lb-ft. Then I asked a different engineer for the actual torque coming from the electric motors, and was told "1,150 Nm," a still-not-insubstantial 848 lb-ft.
Unfortunately, there's no direct conversion for these two torque figures, so it's hard to say with any certainty how much power the production Hummer EV will offer. My best guess is that it'll still be a pretty big number -- more than 1,000 lb-ft, most likely -- but nothing in five-digit territory.
When the Hummer EV goes on sale, it'll compete with a number of other still-in-development electric trucks , none of which claim a torque figure as high as GMC's. Tesla is estimating an even 1,000 lb-ft for its Cybertruck , Bollinger quotes 668 lb-ft for its B2 (which looks a bit like an old Hummer H1 , coincidentally) and Rivian says the R1T will have 829 lb-ft.
The problem here isn't that the 11,500 number is incorrect, it's just very misleading (but hey, a big number looks better in a commercial ). Of course, there's always the outside possibility the truck will actually have 11,500 lb-ft of torque, but I'm not holding my breath. Either way, I'm pretty stoked to see what's in store for this reborn, electric Hummer.
Roadshow
Climb in the driver's seat for the latest car news and reviews, delivered to your inbox twice weekly.
Originally published Jan. 30.
from Via PakapNews