Rubens Barrichello in the Williams FW33 during testing in Jerez
Template: Infobox racing car / Maintenance / stop parameters
The Williams FW33 is 31 Formula 1 racing car of Williams. The constructed by Sam Michael Cart has participated in all 19 races of the Formula 1 2011 season and was controlled by Brazilian Rubens Barrichello, as well as the Venezuelan Pastor Maldonado. Cosworth developed the V8 engine CA2011 with KERS.