This Is When You Should Drive The Tesla Cybertruck With The Tailgate Open

(Tesla)

The Tesla Cybertruck’s bizarre styling isn’t just about making statement.

The pickup’s flat surfaces accommodate the hard-to-bend grade of stainless steel that the body is constructed with, while its triangular shape helps reduce aerodynamic drag.

The sail panels that straddle the bed smooth the air as it passes alongside the vehicle and also create an angled fastback when its locking tonneau cover is closed.

But how well does it work?

SEE IT: TESLA CYBERTRUCK TORN OPEN IN LOW-SPEED FENDER BENDER

EV-focused YouTube channel i1Tesla took a Cybertruck to a wind tunnel and discovered some interesting things.

With the tonneau closed and the vehicle’s air suspension is in its lowest ride height setting, it recorded a .387 drag coefficient (Cd), which is very good for a full size truck equipped with large off-road tires. Lifting it to the medium ride height increased that to .405 Cd and the high driving mode to .445 Cd.

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The off-road and extract modes, which wouldn’t be used at high speeds where aerodynamics play much of a role, were .470 Cd and .535 Cd. But here’s where things get interesting.

Opening the tonneau in low mode results in a .424 Cd, but if you open the tailgate it drops to .413 Cd. There’s an endless debate as to whether or not opening the tailgate on a traditional pickup is better or worse for fuel economy, although many tests point to an open tailgate being a detriment to aerodynamic efficiency.

cybertruck side
(Tesla)

Since the tonneau is a permanent, roll-top design there’s really no need to ever use the truck with it open unless there’s something tall in the bed, but that would have its own aerodynamic effects. There is an even better way to reduce drag, however, if you don’t mind adjusting your eyes.

The Cybertruck’s side mirrors have been designed to be removed easily. The vehicle is required by law to be shipped with them, but not all states require their use and the vehicle has cameras that can provide a side views on its center screen.

Running the truck through the tunnel with the tonneau closed and the mirrors off resulted in a .382 Cd, making it the most efficient configuration.

The truck was also tested with the mirrors off and its oversized wiper parked in a horizontal position, rather than the vertical position it is normally in when not in use, and the figure only increased to .391 Cd.

The Cybertruck does not have an official EPA efficiency rating, due to the fact that it is classified as a type of heavy duty vehicle, but an independent test by Edmunds suggested that it might deliver the equivalent of more than 90 mpg on the highway.