The much-awaited reveal of the Tesla Semi electric truck took place in Hawthorne, California, in typical Elon Musk style. Speculation prior to the presentation was substantially exceeded with its claimed range well beyond the 300 miles (500 km) expected and acceleration figures that place the unladen tractor unit in sports car territory.

After the two Tesla 18-wheel Semis swung into position, Elon Musk stepped out of the high-roof model to begin his presentation. The first statistic presented was the Semi's acceleration to 60 mph (97km/h) from standstill which, he said it does in 5.0 seconds when empty. That is sports car territory. Perhaps even more impressive was the claim of reaching 60 mph fully laden to the maximum permissible total of 80,000 lb (36,288 kg) in 20 seconds. Also remarkable is the claim that the Semi can maintain 65 mph (105 km/h) fully laden up a 5 percent grade.

As to the all-important range figure. When fully laden and travelling at 65 mph, the Tesla Semi can cover an astonishing 500 miles (805 km) on a single charge according to Musk. For those who might quickly compare that to the average range of a diesel truck, which can approach twice that, he added that 80 percent of long-haul routes are less than 250 miles (400 km) one-way, so the Semi can complete most round trips on a single charge. If not, 30 minutes on a Tesla fast charger will enable a topped-up range of 400 miles (644 km). To deflect concerns about the 30-minute wait, Musk pointed out that it takes 15 to 20 minutes to refuel a diesel truck and added that drivers must take rest breaks providing an ideal time to recharge.

When the trucks first pulled into the presentation site, they made a large U-turn in front of the audience before being parked and the snug fit between the back of the cab and the trailer could be seen to open with what looked like hydraulic rams creating room for the cab to turn. The gap immediately closed again as the rig straightened up, eliminating the gap that creates significant aerodynamic drag on conventional rigs.

That innovative feature on the Semi is entirely in keeping with its streamlined cab and surely contributes to the claimed coefficient of drag (cD) of only 0.36. As Musk pointed out, the $2.7 million Bugatti Veyron supercar has a higher cD of 0.38. Also adding to the vehicle's efficiency is the use of four independent wheel motors on the two rear axles of the cab. This avoids the mechanical losses of driving the wheels from a single motor and enables electronic traction control.

Inside the cab the driver's seat is in the centre and placed well forward, leaving room below and to the rear for what is surely a massive battery pack, and while it appears to be large enough to accommodate a sleeper, it is a day cab configuration. In place of the usual collection of levers and switches there are two touch screens mounted either side of the steering wheel.

Unsurprisingly, the electronic systems include advanced driver assistance features such as lane keeping assistance and automatic emergency braking, and extend to autonomous functions such as platooning capability. As part of the data input required for automated driving, two cameras mounted under the large, exterior mirrors, also display images of the side of the rig on the two interior screens.

The weight of the Semi was not specified, raising the question of how much of the 80,000 lb can be payload. Likewise, the retail price was revealed, although Musk gave a hint about its premium over a diesel semi when he claimed that the expected payback period from fuel savings will be around two years under average operating conditions. That claim was based on his assertion that the Tesla Semi will incur operating costs of $1.26 per mile, whereas a diesel equivalent costs $1.51 per mile.

And the final surprise? Out of one of the trucks popped the new Tesla Roadster. Its claimed range is 620 miles (1,000 km) and its zero to 60 mph time is an eye-popping 1.9 seconds. But that is another story.

Source: Tesla

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