Tesla's Semi

The Most Important Thing We Don't Know About Tesla's New Semi

Elon Musk hyped up almost every bit of the new Tesla Semi except the most crucial detail—the truck's weight.

By Avery Thompson

Last month, Tesla unveiled the next step in its vision of electrifying the future of transportation: the Tesla Semi, a battery-powered truck capable of hauling cargo across the country. The announcement came with a laundry list of stats, including a 500-mile range and 0-60 in five seconds, but one very important statistic was curiously missing: the weight of the vehicle.


For a freight truck, the weight of the vehicle with no cargo—called the empty weight—is an extremely important statistic because it affects the total amount of cargo the truck can carry. In the United States, semi trucks are limited to a weight of 80,000 pounds or less, including the empty weight of the vehicle. The heavier the truck, the less it’s allowed to carry.

Building a light truck is a challenge for any auto company, but it’s especially hard for Tesla because batteries still don’t have the same energy density as fossil fuels. This means that Tesla needs much more weight to get a semi that has a similar range to existing trucks.

Real Engineering calculates how much the Tesla Semi weighs and whether the lower cargo space is worth the fuel savings:

It’s not easy to find out how much the Tesla Semi weighs, but it’s possible to calculate it given the stats included in Tesla’s announcement and some complicated math. Real Engineering runs through the calculations and comes up with a value of 17,400 pounds for the empty weight of the truck.

This is actually a pretty average weight for trucks in this class. That means the Tesla Semi is capable of hauling approximately the same amount of cargo as a standard semi truck. However, this comes at the cost of range: a diesel semi can get upwards of 1,000 miles before refueling, while the Tesla truck only gets half that.

Still, the fuel savings would make the Tesla Semi competitive with traditional trucks over short and medium distances. Not bad for an unproven, next-generation technology.

Source: Real Engineering