The Renault R23 is a Formula One car that competed in the 2003 Formula One season. The driver lineup were Jarno Trulli and Fernando Alonso who replaced Jenson Button who left for British American Racing. The chassis was designed by Mike Gascoyne, Bob Bell, Tim Densham and John Iley with Pat Symonds overseeing the design and production of the car as Executive Director of Engineering and Jean-Jacques His leading the engine design. A "B Specification" car named the Renault R23B made its debut at the British Grand Prix and used for the remainder of the 2003 season.