[3][4] While Williams was able to compete and take a couple of victories home in recent years, the FW27 proved not to be up to the same performance levels as some of the other teams' cars.

From the Italian Grand Prix onwards, Heidfeld, who was injured, was replaced by Antônio Pizzonia, who had previously been Webber's teammate at Jaguar in 2003.

The team ended the season winless for the first time since 2000 in fifth place in the Constructors' Championship, failing to meet their own high expectations.

BMW-Williams went into 2005 season with renewed major sponsorships such as Allianz, FedEx, Hewlett-Packard, Reuters, Oris, Hamleys, Budweiser, Petrobras and Castrol.

On 27 September 2005, future four-time world champion Sebastian Vettel conducted his first ever test in a Formula One car in a Williams FW27 Circuito de Jerez.