Did Mercedes make two different cars for 2019?

On the 2nd week of testing in Barcelona Mercedes brought a completely different car

(GMM) Sergio Perez has floated a fascinating theory about Mercedes.

In week two of the Barcelona test, Mercedes brought a 'B' car to the track. An engineer said "every aerodynamic surface" of the silver car has been changed.

Some said it was a reaction to Mercedes' realization that it is lagging behind Ferrari by half a second per lap.

"Ferrari looked very good in Barcelona, that's for sure," Racing Point driver Sergio Perez told Marca.

"But maybe Mercedes didn't reveal all their cards. It seemed somewhat strange to me that they brought two different cars to the tests.

"It is possible that they are designed for different types of tracks," he added. "We see a lot of strange things in formula one."