Mercedes are to unveil their 2012 car on the first day of pre-season testing at the Circuit de Catalunya in Barcelona next Tuesday.
Michael Schumacher and Nico Rosberg drove an interim version of last year's W02 at last week's test in Jerez after the team opted to delay launching the W03 in order to spend further time developing the car.
The pair spent three days building up data on the new Pirelli tyres and their hard work paid dividends as the team topped the timesheets on Wednesday and Thursday.
Focus will switch to the W03 on Tuesday when the covers are taken off the car in the Circuit de Catalunya's pit lane less than an hour before the four-day test gets under way.
Schumacher is scheduled to drive the car on Tuesday and Thursday with Rosberg behind the wheel on Wednesday and Friday.