Williams deputy team principal Claire Williams says the car launched on Friday is by far the final design, with updates scheduled for the first round in Australia.
The Grove-based outfit uncovered the Mercedes-powered FW38 in an online reveal, ahead of the first pre-season test from the 22-25 February at the Circuit de Barcelona-Catalunya.
Williams says the team enters the new season in a strong position and is confident it can build on the strengths shown in 2015, as well as ironing out the weaknesses of the FW37.
"2016 promises to be a very competitive year in Formula 1 and there will be a number of strong teams who have us in their sights," she said.
"We are confident that we have made a step forward over the winter and that the FW38 will build on the strengths of the FW37 and address some of its weaknesses.
"We started design work on the car earlier than normal and hopefully this extra development time will stand us in good stead.
"The car we are launching is by no means the final product. We are already planning updates for Melbourne and will be pushing for constant improvements over the course of the season. Williams enters 2016 in a strong place.
"We have a great team of people and over the past two years we have started to regain our competitive edge. Now we need to build on that and take this team back to where we all want it to be.”
