Meanwhile, Mercedes believe Red Bull have the fastest car going into the opening race of the season.
“There are a lot of unknowns,” Mercedes strategy director James Vowles said.
“No-one up and down the paddock can pinpoint exactly where they are.
“But there are a few trends that have come out. I’d say Red Bull are ahead on performance. They are the class act.”
Vowles added: “Red Bull are a fierce adversary, they’ve got a strong package and clearly came out of the box very, very quick.