The Bugatti Chiron improves on the formula laid out by the iconic Veyron in every single way—except, that is, the “official” top speed. Electronically limited to 261 mph, the Chiron is currently slower than the Veyron Super Sport World Record Edition, and Bugatti’s not going to attempt an unrestricted top speed run in the Chiron until next year. Thanks to a new feature in Popular Mechanics, we now know why that is.
It turns out that in building their new supercar, Bugatti managed to almost outdo current street tire technology. The gravitational and thermal forces a tire must withstand at speeds above 250 mph are monumental, and while the Chiron currently rides on Michelin’s grippiest, range-topping rubber, the company’s engineers have yet to figure out their theoretical limit. Bugatti test pilot Andy Wallace believes Michelin will eventually approve a top speed of above 280 mph for the Chiron, but he also notes there’s currently no tire available that can survive at the magical 300 mph mark.
That’s a fine line to walk—less than 20 mph between running the rubber at the limit and everything falling apart—but the Bugatti Chiron is nothing if not obsessively engineered. To keep you from killing yourself and ruining a $2.7 million piece of automotive art, the Chiron is limited during everyday use to a pedestrian 237 mph.To find that last 24 mph, you first have to insert a special “top speed key,” similar to the famous “red key” found in a Dodge Challenger SRT Hellcat, except about forty times the price.
Once the key is in position, the Chiron will scan itself for any problems, then lower the chassis, deploy the rear wing, and tighten the suspension. Only then can you give it the business, and only in a straight line—the top speed mode will disengage if you move the steering wheel beyond a quarter turn, or if the car’s computer senses either the ABS or traction control kicking in. That’s good, because at that speed you and the car are covering a mile every ten seconds.
Other highlights from the feature include quirky build details like the fact that the taillight bezels are crafted from a single 441-pound piece of aluminum, and a rundown of the Bugatti Chiron’s different driving modes, one of which actually allows adventurous owners to drift the thing. 2018 can’t come soon enough.