Jaguar said that prototype model was equipped with a slightly more powerful version of the standard XFR's 5.0-liter V8 with additional horsepower being liberated by a remapped ECU, a modified air intake and exhaust system and revised supercharger settings. It was also fitted with minor aerodynamic and safety modifications that were made to meet the requirements for a Bonneville run. According to the British automaker, no internal engine components were changed and the six-speed automatic transmission was standard, including the gear ratios.
Video: Jaguar XFR Prototype tops 225 mph at Bonneville Salt Flats
At the Detroit Show, Jaguar revealed a specially modified XFR prototype that recorded a top speed of 225.7 mph (363.2 km/h) during a secret speed trial at the iconic Bonneville Salt Flats in Utah last November. The XFR prototype beat Jaguar's previous speed record of 217.1mph (349.4 km/h) that had been set back in 1992 by the XJ220. The man behind the wheel of the fastest Jag ever was Paul Gentilozzi, owner of Rocketsports Racing who led the Jaguar XKR to five series victories between 2001 and 2006 in the Trans Am series in the USA.