Mercedes have revealed the new car they hope will claim a record-equalling fifth consecutive world championship double this year.
Valtteri Bottas drove the car at a cold Silverstone on Thursday morning.
World champion Lewis Hamilton is scheduled to drive the W09 in the afternoon, after the car is officially unveiled.
“We’ve tried to stay true to our design philosophy and develop an already solid base,” said Mercedes boss Toto Wolff.
The new car appears to be a design evolution of last year’s successful car.
Wolff said the team had tried to keep the strengths of its overall pace as F1’s fastest car, but iron out the flaws that made it uncompetitive at certain types of circuit.
“We hope we have kept the good character traits of the diva,” he said.
“We all like divas, but sometimes she was a bit difficult to understand and this is the area where we worked the most, trying to understand and preserve the speed in the car and find more driveability.
“Because the regulations have stayed stable, there is not a lot of difference. The most visible change is aerodynamic and how tight the packaging is of the car and how closed up the bodywork is.”
Wolff said Hamilton was “extremely motivated” for the new season and expected him to sign a new contract to stay at Mercedes beyond the end of this season “in a few weeks”.
The Briton will speak later on Thursday.