Striking new facts have surfaced about the power potential of the all-electric Tesla Semi truck, which is three times as powerful as diesel versions of the same weight in terms of the total power of its three electric motors.
A short video from Donner Pass in the northern part of the Sierra Nevada (USA) has been posted online, where a fully loaded Tesla Semi easily outruns a group of heavy-duty tractor-trailers on a 6 percent climb. The Semi first overtakes to the right and then to the left on a rounded bend in the road, and after completing the maneuver, it just as easily takes the rightmost lane and races downhill.
An experienced driver will immediately realize from the 29-second video that the Semi is driving without fatigue and with a lot of power in reserve, as if it were an electric car rather than a truck. There is no mistaking the comparison with the rapid movement of a car: as it turned out, the manufacturer used rotors with carbon sleeves in the electric motors – like in the Tesla Model S/Model X Plaid. This made it possible to squeeze the maximum output from the power units.
Although the manufacturer does not give the exact values of peak or continuous output power, its brief specification shows that with a full load (37,195 kg), the truck can accelerate from 0 to 96.5 km/h (60 miles) in just 20 seconds. The diesel version of the mainline tractor with a loaded semitrailer is not able to achieve such a rapid acceleration.
I had some thoughts about how to (safely) capture some video of the Tesla Semi vs diesel semi’s going up a steep grade. The average grade ascending the Donner Pass is 7% up to 16%. This is some of what I captured. #Tesla #teslasemi Tesla runs these semi’s daily, fully loaded up… pic.twitter.com/eEHwc1s0DB
– Zanegler (@HinrichsZane) July 14, 2023
Tesla loves the trinity
The new facts about the transmission indicate the beginning of a number of solutions that have not yet been put into operation. Among the main ones is a transmission scheme based on three independent electric motors, not four, as announced in 2017 at the beginning of the design of this electric truck.
The three-engine system has proven its worth. The front axle is not involved in the drive; in the operation of electric power units, only the two rear axles – the second and third, i.e. the extreme rear axle – are driven. The second, i.e., the middle one relative to the three-axle chassis, has one electric motor permanently connected through a single-speed gearbox. This is a highway worker.
The other two motors are used on the rear axle to drive the wheels individually – left and right. They are optimized for acceleration and torque. Depending on the circumstances (especially the speed and accelerator pedal position), the two rear motors automatically and seamlessly engage or disengage from the drive axle to minimize energy loss.
No noise, no buzz and saves resources
There is another interesting advantage of the Tesla Semi. It manifests itself during descents. Whereas traditional diesel trucks rely on the engine brake, the Semi can maintain a constant speed while regenerating energy.
This feature saves time and money, as the Tesla Semi’s regenerative braking significantly reduces brake wear, transmission wear, and engine wear. In addition, the quiet operation of the Tesla Semi contrasts sharply with the noise generated by the motor brakes of diesel trucks.
Semi has two versions of the battery pack. With a standard battery, the range is 483 km, and with an enhanced battery, it is 804 km with a capacity of 600 kWh or 1000 kWh (1 MWh), respectively. In fast charging mode, you can get up to 70% of the charge in 30 minutes.
It turned out that the Tesla Semi uses mass-produced parts and transmission components borrowed from other models, including electric motors and inverters, heat pumps, and even an infotainment system. This made it possible to achieve a much higher level of reliability compared to the alternative scenario of developing completely new systems for a relatively small-scale vehicle (compared to millions of passenger cars).
