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.