The Tesla Roadster has 10,000 Nm according to the specifications. The GMC Hummer has 15,500 Nm and if you have an electric motor installed in your Porsche, you suddenly have 3,900 Nm. With such absurd numbers you would think that you can change your tires after every traffic light, because you accidentally smoked them. The reality is different: the specified torque for an electric car is often somewhat misleading.
We do not mean to say that electric motors are weak things. No, an EV does have a lot of torque, and also revs from zero. The claims of thousands of Newton meters are a bit exaggerated. This is probably because the marketing department has been meddling against the specifications.
He looks a bit angry; suffer from a morning Hummer | Photo: © GMC
Torque from electric to the wheels is different than to the motor
The torque that you read in the brochure of a fuel car is often the torque of the engine itself. Often also referred to as torque ‘at the crankshaft’. Once the power passes through the gearbox and differential, the torque changes through the gears. Just look at the gears on your bike: you can pedal up easier (more torque), but you will go slower.
In the case of the Tesla Roadster and the GMC Hummer, this refers to the torque at the wheels. Because electric motors rev much more than a petrol engine, the car can be permanently in a kind of low gear. If it were a cyclist, the electric motor would always pedal very fast. The torque at the electric motor would give a completely different picture.
How many Nm do petrol cars have on the wheels?
Youtube Channel Engineering Explained made a good video about it a few years ago. He explains that according to the same calculations, a Dodge Demon has about 14,000 Nm in first gear. At the wheels, because at the engine it is more than 1,000 Nm. If you compare apples to apples, you can therefore make a better representation.
And more importantly, the Demon can do a wheelie | Photo: © Dodge
Website CNET is told by BMW that an electric prototype with 10,000 Nm at the wheels has more than 1,100 Nm at the electric motors. By the way, you cannot ‘divide it by ten’ as standard, because the torque at the wheels depends on the transmission and the speed of the electric motor. Again: EVs have a lot of torque, but not that much.
What do the license plate data say?
Incidentally, there are no production copies of the new Tesla Roadster yet and no torque has been specified for the Plaid models. Not even in the license plate data. The Hummer EV has (as far as we know) no European type approval, so we can’t see how much torque the huge SUV would have on license plate. For example, a Lucid Air has 1,390 Nm on the license plate.
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