Mercedes team principal Toto Wolff has conceded it is "mentally difficult" to enter a new campaign off the back of a challenging year in F1.
The Brackley-based team arrived in Bahrain for the pre-season test knowing it would need to take significant steps forward with the W14 to stand any chance of competing with Red Bull and Ferrari in the upcoming season.
The W13 last year was plagued with issues, from porpoising and poor drag efficiency to weight troubles and difficulty in correlating data between track and simulation.
The new machinery has made a positive start on track and with times largely irrelevant during testing, all focus is on ensuring systems are functioning ahead of the opening round of the year in Bahrain next weekend.
"Obviously, mentally it is always difficult to start with a car that was not on par last year and hopefully see something that is better," said Wolff.
"This is where the excitement comes from but equally, you want to get it right."
Porpoising solved?
Porpoising was the cause of headaches up and down the grid last season, with the FIA eventually taking measures to limit the effect of the aerodynamic phenomenon.
These steps included a 15mm raise of the floor edge for the new year and addressing the issue, Wolff insisted: "The porpoising is gone essentially, that is a good thing."
"I think we have a solid base now to work from and try to optimise the car."