Even though the Rivian R1T looks fairly conventional and quite similar to other trucks, at least in terms of its overall look and proportions, its makers say it is considerably more aerodynamically efficient compared to rivals. Rivian says the R1T has a drag coefficient of 0.30 Cd, compared to around 0.44 Cd for the Ford F-150 Lightning and over 0.5 Cd for the GMC Hummer EV.
Now, with the help of AirShaper, an online aerodynamics platform that is aimed at both designers and engineers, the application’s creators were able to verify the claims made by Rivian. They used what they say is an accurate scanned 3D model of the Rivian R1T, provided by A2MAC1, which they ran through the simulation and actually got pretty close to the manufacturer claim with 0.322 Cd.
Gallery: Rivian R1T Virtual Wind Tunnel by AirShaper
The AirShaper app has a feature that allows you to see 3D pressure clouds generated by the model as it is run through a virtual wind tunnel. On the R1T model they tested in the video, a point of high pressure actually appeared on top of the right A-pillar, but not on the left. They pinpointed its cause as a couple of misaligned panels that affected the flow of air and that the defect was present on the truck that were 3D scanned.
It’s surprising how such a small and not immediately visible defect can have such a big impact on air flow, but this simulation shows that it does and how much it actually does. But it’s still impressive how close the result they got out of the simulation is to the manufacturer claim, especially since automakers are usually quite optimistic when they announce a vehicle’s drag coefficient, often rounding down the number to make it stand out.
What’s interesting and is stated in the video is that the difference between the manufacturer claim and the actual result in this case may just be down to the choice of wheels. With a set of flat aero style wheels that allow air to pass over easier than it would over a rim with spokes and lots of open spaces, the R1T should actually come very close to matching the official number.