"In Australia we had basically a construction site, while McLaren's house was finished long ago," world champion Sebastian Vettel said by way of analogy to Germany's Auto Bild.
"So second place (in Melbourne) was not too bad."
Team advisor Dr Helmut Marko agrees: "Vettel spent most of the last day of the testing in Barcelona in the pits.
"Our car is not yet mature," he added, referring to the Renault-powered RB8.
Team boss Christian Horner said the team brought out "only 60 per cent" of the car's potential in Australia.