1 for the air conditioning system. 1 transmission oil radiator. 1 differential oil radiator. 1 engine oil radiator It has a (normal condition) and (after lowering to the ground), and a frontal area of . This gives it a drag area, the product of drag coefficient and frontal area, of . Engine power output According to Volkswagen Group and certified by TÜV Süddeutschland, the W16 engine utilised by the Veyron has a power output of , and generates of torque. Top speed German inspection officials recorded an average top speed of the original version at during test sessions on Volkswagen Group's private Ehra-Lessien test track on 19 April 2005. This top speed was almost matched by James May on Top Gear in November 2006, at the Ehra-Lessien test track, at . May noted that at top speed the engine consumes of air per minute (as much as a human breathes in four days). Back in the Top Gear studio, co-presenter Jeremy Clarkson commented that most sports cars felt like they were shaking apart at their top speed, and asked May if that was the case with the Veyron at . May responded that the Veyron was very controlled, and only wobbled slightly when the air brake deployed. The car's normal top speed is listed at . When the car reaches , hydraulics lower the car until it has a ground clearance of about . At the same time, the wing and spoiler deploy. In this handling mode, the wing provides of downforce, holding the car to the road. Top speed mode must be entered while the vehicle is at rest. Its driver must toggle a special top speed key to the left of their seat, which triggers a checklist to establish whether the car and its driver are ready to attempt to reach . If so, the rear spoiler retracts, the front air diffusers shut, and normal ground clearance drops to . Braking The Veyron's brakes use cross drilled, radially vented carbon fibre reinforced silicon carbide (C/SiC) composite discs, manufactured by SGL Carbon, which have less brake fade and weigh less than standard cast iron discs. The lightweight aluminium alloy monobloc brake calipers are made by AP Racing; the front have eight titanium pistons and the rear calipers have six pistons. Bugatti claims maximum deceleration of 1.3 g on road tyres. As an added safety feature, in the event of