Image Credit: YOUCAR / YouTube.Driving an SUV onto the wall of a tunnel, across its ceiling, and back onto the road sounds like the sort of stunt that would normally involve CGI. Chinese automaker Voyah decided to try it with an actual production-spec electric SUV instead.The attempt took place inside a closed tunnel in Wuhan, China, where specially constructed ramps allowed the vehicle to transition from the road onto the curved tunnel wall. From there, it completed a full rotation around the inside of the tunnel while continuing to travel forward.According to a video published by the YOUCAR YouTube channel, the vehicle was a Voyah Passion S, an electric SUV from Dongfeng's premium brand. Voyah says the vehicle was stock, carrying its full battery and driver-assistance hardware without weight reduction.AdvertisementAdvertisementPulling it off required far greater precision than simply flooring a powerful EV toward a ramp. The Passion S needed to enter at roughly 80 mph and at an angle of about 16 degrees, with only a narrow speed window separating a successful run from a potentially very expensive mistake.The SUV Actually Drives Across The CeilingAlthough it looks like a conventional loop when viewed from certain angles, the Passion S isn't traveling around a vertical circle like a car on a Hot Wheels track. It continues moving down the tunnel while simultaneously rotating around its inner surface, creating a helical path.The ramps are crucial because they smoothly redirect the SUV onto the tunnel wall. Once there, the vehicle needs sufficient circumferential speed to remain against the curved surface as it passes through the inverted portion of the maneuver.Voyah reportedly targeted approximately 130 km/h, or 81 mph, for the attempt. The allowable margin was said to be only around 2 to 3 mph, making the approach speed and trajectory critical.The Physics Appear To Check OutImage Credit: YOUCAR / YouTube.Independent calculations based on the footage suggest the stunt is physically plausible. Estimates put the radius of the Passion S's path at roughly 4.4 meters, with the SUV completing its rotation in approximately 2.5 to 3 seconds.AdvertisementAdvertisementThat would give it an estimated circumferential speed of around 33 to 40 km/h. Using the theoretical minimum speed required to maintain contact at the top of a circular path, the threshold works out to roughly 24 km/h for that estimated radius.Those numbers leave the Passion S above the theoretical minimum visible in the footage. Real-world factors, including changing tunnel geometry, suspension movement, tire behavior, and speed variations, make the actual maneuver considerably more complicated than a simplified calculation suggests.This Is A 5,500-Pound Electric SUVVoyah says the Passion S used for the successful run retained its full production equipment. The SUV produces 637 horsepower and 564 lb-ft of torque from its electric powertrain and uses an 800-volt electrical architecture.Weight arguably makes the spectacle even more impressive, as the Passion S weighs well over 5,500 pounds, meaning its tires, suspension, wheel bearings, and structure experience substantial loads as the SUV transitions onto and off the tunnel surface.AdvertisementAdvertisementMass doesn't increase the theoretical minimum speed required to remain against the ceiling because it cancels out of the basic circular-motion calculation. It certainly matters when several thousand pounds of SUV come back down onto its suspension.Voyah Says There Were No Special EffectsThe polished promotional footage initially attracted skepticism online, which isn't particularly surprising given how convincing modern visual effects can be. Voyah subsequently showed an uncut recording of a successful attempt, while separate footage reportedly shows an earlier run ending with a much rougher return to the road.That failed attempt may actually make the successful run easier to appreciate. There was clearly little room for error when sending a roughly 5,500-pound electric SUV around the inside of a tunnel at highway speed.Mercedes-Benz famously depicted an SLS AMG performing a similar maneuver in a 2010 advertisement, although the finished sequence relied on digital effects. Sixteen years later, Voyah appears to have taken the considerably harder route and actually driven its SUV across the ceiling.AdvertisementAdvertisementIf you want more stories like this, follow Guessing Headlights on Yahoo so you don't miss what's coming next.