Top speed records are elusive primarily because it takes more than just insane horsepower but also tremendous tire capability, superb downforce, and also slippery aerodynamics to overcome drag. A special version of the potent Bugatti Chiron just broke the record and also broke the 300 mph barrier. It's a first for a roadgoing, street legal machine, and it's nothing short of astounding. But just look at this thing. Aside from the orange stripes, it looks all business.
The record was shattered by Bugatti's Andy Wallace, the brand's test pilot helming a Chiron-based prototype on the Ehra-Lessien track in Germany. The power comes from the Chiron's W16 engine at a speed of 304.773 mph. It beat Bugatti's own Veyron Super Sports that hit 267.856 and even the Koenigsegg Agera RS, which was able to hit 284.550 mph. All this was accomplished on the Ehra-Lessien's 5.4 miles of straightaway.
Not much is known about the special long tail version of the Chiron, but the longer back end serves to add downforce without increasing the car's drag coefficient (0.35 in Top Speed mode). Power from the W16 engine in stock mode is 1,479 horsepower and 1180 lb.-ft. of torque, though this one could've been tweaked for more power.
Other changes were made in the form of drilled vents in the front to reduce turbulence in the wheel wells, and there's also roll cage and a Sparco racing seat for the driver. It also looks like the long tail may have been lowered, which make sense. Hopefully, we'll get more information soon after everyone recovers from the shock and awe of the accomplishment.
Bugatti was assisted by Italy's Dallara Automobili, an Italian chassis manufacturer that makes its own supercar (Stradale) and provides chassis to Formula 3 racing teams. The tires are also quite special thanks to Michelin who provided Pilot Cup Sport 2 tires that were custom reinforced to handle 5,300 Gs of force while still being legal for street use. We can't even imagine how much a set costs (probably more than your entire car).
The brand can now brag that their record will be REALLY hard to beat. Other manufacturers/tuners like Hennessey (with their upcoming Venom F5) are aiming for 300+ mph, as they announced just days ago, uncoincidentally. We'll see how long this record stands. But for now, Bugatti can officially say they have the world's fastest street-legal car.