German inspection officials recorded an average top speed of the original version of 408.47 km/h (253.81 mph) during test sessions on the Ehra-Lessien test track on 19 April 2005.
This top speed was verified by James May on Top Gear in November 2006, again at Volkswagen Group's private Ehra-Lessien test track. May noted that at top speed the engine consumes 45,000 litres (9,900 imp gal) of air per minute (as much as a human breathes in four days). The Veyron has the highest top speed of any street legal production car. Back in the Top Gear studio, co-presenter Jeremy Clarkson commented that most supercars felt like they were shaking apart at their top speed, and asked May if that was the case with the Veyron at 407 km/h (253 mph). May responded that no, the Veyron was very controlled, and only wobbled a tiny bit when the air brake deployed. May further commented, “Absolutely yeah, it’s totally undramatic. But I would give you a bit of a warning: It’s a bit disorientating doing that sort of speed, because after I came off the banking, I was slowing down to stop, and you know how you get a bit impatient and think ‘I’ll just open the door’; fortunately I looked back at the speedo, and I was still doing seventy.”
On 4 July 2010, Bugatti's official test driver Pierre Henri Raphanel piloted the Super Sport edition and was clocked at an average of 431.072 km/h (267.856 mph) on the same track, taking back the title from the SSC Ultimate Aero TT as the fastest production vehicle of all time. The 431.072 km/h mark was reached by averaging the Super Sport's two test runs, the first reaching 427.93 km/h (265.90 mph) and the second 434.20 km/h (269.80 mph). The record run was certified by the German government and the Guinness Book of World Records.
The car's everyday top speed is listed at 350 km/h (220 mph). When the car reaches 220 km/h (140 mph), hydraulics lower the car until it has a ground clearance of about 9 cm (3.5 in). At the same time, the wing and spoiler deploy. In this handling mode the wing provides 3,425 newtons (770 lbf) of downforce, holding the car to the road.
For top speed mode the driver must, while at rest, toggle a special top speed key to the left of the driver's seat. A checklist then establishes whether the car and its driver are ready to attempt to reach 407 km/h (253 mph). If so, the rear spoiler retracts, the front air diffusers shut, and normal 12.5 cm (4.9 in) ground clearance drops to 6.5 cm (2.6 in).