Wolff acknowledges: 'The car has less balance'

The test days leading up to the Formula 1 season can bring unpleasant surprises. Last year, for example, it became clear that porpoising was a major problem within the new aerodynamics rules. Mercedes in particular continued to suffer from this bouncing of the car throughout the year.

The team's hope was that Mercedes would come out of the test days a bit better this year, but according to Wolff, new problems have surfaced. "The car is out of balance this morning," Wolff acknowledged during the second day of testing in Bahrain. "You can see we're leaving black marks on acceleration. It's hot and we didn't find the right set-up in these conditions which is part of the learning with this car. It's not the driver who is over driving the car, the car isn't giving us enough grip from the rear."

'We are also keeping some things secret'

Wolff was also asked if he is happy with where the team currently stands in relation to the competition. "[Red Bull and Ferrari] they're fast. No surprise there," Wolff said immediately. "It's difficult to judge, everyone is playing around with fuel loads and hiding on engine modes. We are still hiding a little bit. You need to wait for the three days running and also when the soft tyres come on."