Helmut Marko says that Ferrari's sandbagging tactics in pre-season testing could spell trouble for Red Bull Racing in Melbourne next week.
Several times on the penultimate day of testing Barcelona, Sebastien Vettel ostensibly lifted in the third and final sector of his fast lap, deliberately refraining from putting in a lap which reflected the Ferrari's speed.
"Ferrari is very strong and reliable as well," Marko told Red Bull's Servus TV channel.
"That's the difference to last year.
"What worries me somewhat is I know Vettel very well. He provocatively lifted on his fastest lap on the start and finish straight. Everybody could tell.
"And if you do something like this, then your self-confidence and the knowledge about having a lot more in the car is huge."
Kimi Raikkonen was less protective of the SF701H's potential, setting the fastest lap overall on the final day of testing with a sub-1m19s round of the Circuit de Catalunya.
But Marko insisted that without the knowledge of fuel loads or engine mapping, it was impossible to fully appreciate the efforts of both Ferrari and Mercedes, the two teams faster than Red Bull racing in Spain.
"Nobody has shown his cards properly," he said.
"If you carry 10 kg more fuel, you gain about 0.35 seconds. Furthermore, engine mappings differ. This can gain you up to one second - or it doesn't.
"A lot has been kept in the dark. But if the race [Melbourne] would have taken place with the same kind of temperatures we had [in testing] then Ferrari would be in front, for sure."
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