Williams launched their 2013 challenger the FW35 on the first day of the second first pre-season test in Barcelona.
The new car features a revised front wing, smaller sidepods and a modified exhaust.
Williams Technical Director Mike Coughlan siad: “It’s a better, more refined Formula 1 car than the FW34 and I think everyone involved in the project can feel proud of the work they’ve done.”
Just hours after the team unveiled their car the FIA suggested its exhaust was illegal according to a BBC report. Williams was not the only team affected with the exhaust on the Caterham also considered illegal.
A Williams spokesperson confirmed that the team would be seeking further clarification.
Pastor Maldonado was the first driver to get behind the wheel of the FW35 on Tuesday setting the fifth fastest time after completing 86 laps.