Has the Tesla Semi set a new standard for truck aerodynamics

With the introduction of the electric Semi Truck, Tesla is now aiming to redefine truck aerodynamics.

Bulky boxes on wheels

Heavy-duty transport like trucks and buses, produce around a quarter of all road transport CO2 emissions in the EU – that’s around 5% of the EU’s total greenhouse gas emissions. So it’s no surprise that the road transport sector is feeling the pressure to reduce its fuel consumption. One way to get those numbers down, is by improving the aerodynamic efficiency of trucks and trailers.

A truck’s design is particularly aimed at making maximal use of every cubic centimeter that is allowed, without thinking about aerodynamics. And that’s too bad, because a streamlined truck can save transport companies loads of money. Despite a lot of research and attempts to design curved vehicles, bulky trucks are still filling up our highways.

Airshaper puts Tesla to the test

Tesla, however, is now showing us what we are missing, thanks to a radical methodology. For the design of their electric Semi Truck, Tesla started from scratch. They ignored all previous design rules, with one ultimate goal: to double the truck’s aerodynamic efficiency compared to normal trucks, making its design as streamlined as that of a normal road car.

The Belgian start-up Airshaper wanted to find out if Tesla succeeded. AirShaper is an online aerodynamics platform that can calculate an object’s precise aerodynamics based on a digital 3D model. They created a 3D replica of both a Semi Truck and a conventional truck in its most competitive setup to make the comparison as tough as possible.

Minimal pressure

Aerodynamics are expressed via the drag coefficient Cd. The lower a vehicle’s coefficient is, the better. Airshaper’s research led to a remarkable outcome: based on the 3D printed model, they estimated that the Semi Truck has an estimated drag value of 0.35, compared to 0.43 for the reference truck. This means the Tesla model reduces drag by 20%.

So how did the Tesla designers pull this off? The large, flat front of a regular truck causes a lot of pressure build-up, so that was the first thing that had to change. A narrow shape of the cabin reduces this pressure build-up and aligns it with the trailer, which has been pulled to the cabin as close as possible for minimal turbulence. Tesla also replaced the side mirrors with short camera sticks to reduced pressure on the front surface. Further down, the rear wheels are completely shielded to take away air disturbance.

Since the Airshaper study is based on estimations, it’s important to point out that these results are far from accurate. But it does indicate that Tesla managed to drastically improve the aerodynamics of a large truck. Even if we don’t know the exact percentages, it’s safe to say that Tesla has created a truck with aerodynamics that beats every other truck out there.

Source: www.airshaper.com/reports/truck.pdf www.airshaper.com/reports/tesla_semi.pdf