Taking a vehicle like the Bugatti Veyron through to its top speed isn’t easy. In fact, it requires months of planning and hasn’t been achieved by many people outside of Bugatti.

However, back in 2011, a Veyron owner set out to exceed 400 km/h (248.5 mph) in the French hypercar. The location for the daring attempt was Germany’s Autobahn.

On the day of the attempt, owner Radim Passer took to a straight ribbon of Autobahn early in the morning to avoid any traffic. Unleashing the vehicle’s 987 hp, quad-turbo 8.0-liter V16 engine with his right foot, Passer was able to get the Veyron up to 375 km/h (233 mph). However, Passer was later told by Bugatti that the ambient temperature was too low for the vehicle’s top speed mode to be activated.

We don’t recommend trying to replicate this feat.

With this in mind, another attempt was made to exceed 400 km/h. Once again, top speed mode couldn’t be enabled. Upon inspection, Bugatti engineers discovered that the transmission needed to be replaced.

Fast forward to 2015 and the hypercar had a new gearbox and fresh rubber. Setting out once again to be the first person to take a road-legal car to 400 km/h on the Autobahn, Passer finally achieved his goal, reaching a top speed of 402.5 km/h (250 mph).

Bugatti offers Veyron owners the chance to max out the hypercar at its Ehra-Lessien testing facility in Germany. Doing so is very expensive and clearly not as dangerous and perhaps exhilarating as maxing one out on a public road.

Unfortunately for Passer, he no longer holds the record for the highest speed achieved on a public road. The record is now held by a Koenigsegg Agera RS that averaged 447 km/h (277.87 mph) in November last year.