2,977-HP YangWang U9 Could Theoretically Hit 400 MPH (With A Whole Lot Of Asterisks), Engineer Claims

You’ll never actually be able to use a car capable of hitting 300 mph on public roads, and it would be so wildly dangerous to try that I’d hope you’d go straight to jail (if you survived). But that doesn’t mean it isn’t still cool to see the Bugatti Chiron’s top-speed record fall, even if the record was broken by an EV built in China that no one reading this will likely ever see on the road, much less get a chance to drive. I mean, it’s not every day a new car gets crowned the fastest car in the world, even if Yangwang only plans to build 30 examples.

Back in August, the U9 hit 293.54 mph, but that was only the Track Edition. Only a few weeks later, the Yangwang U9 Xtreme hit 308 mph, officially making it the fastest street-legal production car ever built. That’s got to be pretty exciting for young car enthusiasts, but you know who else is excited? Engineers, including our favorite engineer-turned-YouTuber, Jason Fenske of Engineering Explained fame. And with a new record set, you better believe it’s time to break out the whiteboard, crack open some dry-erase markers and talk numbers. 

As Jason points out, with 2,977 horsepower, the U9 Xtreme is easily the most powerful production car ever, and with motors that can hit 30,000 rpm, it also has the fastest-spinning motors ever used in a production car. Plus, its 1,200-volt system makes it the highest-voltage production vehicle ever, and it also offers the fastest battery discharge rate at 30C. The question is, though, with enough room to run, how much faster could the U9 Xtreme actually go, and could it hit 400 mph?

Unfortunately for anyone who’s hoping to see Jason calculate the U9 Xtreme’s One True Top Speed, there are a few too many variables at play here to get more than a rough estimate. Still, it isn’t like he’s out here assuming a spherical cow. Plug a rough estimate of the U9 Xtreme’s drag coefficient into the formula, and a little back-of-the-napkin front-of-the-whiteboard math gets us to a theoretical top speed of 415 mph. That’s pretty darn fast. 

That’s assuming a drag coefficient of 0.24, though. If drag is as high as 0.3, that same formula says you’d come up short of 400 mph after topping out at a mere 385 mph. On the other hand, if it’s even more aerodynamic than initially assumed, a drag coefficient of 0.2 would theoretically give the U9 Xtreme a top speed of 440 mph. Despite spending four years at Georgia Tech, I never once took an engineering course, so I can’t tell you which one is more accurate, but I am still able to send an email, so hopefully, their PR rep gets back to me with an official drag coefficient soon. 

Does that mean we’ll see Yangwang shoot for 400 mph next month? Probably not. As Jason points out, perhaps the biggest limitation on a real-world test like this is space. Where the heck are you going to actually take the U9 Xtreme to test its actual top speed? On top of that, you also need tires that you can safely use at speeds well above 400 mph that are also street legal, and Michelin doesn’t exactly have a set they can pick up at Costco. And can the battery actually put out enough power for long enough to get the car past 400 mph? Does it have the necessary cooling? Heck, does it even have the gearing to cross 400 mph?

From there, the video only gets even nerdier (in the best way possible, I promise), so instead of reading my words, why not give the whole thing a watch?