Ferrari literally powered its way back to the front in Bahrain, according to Red Bull's Dr Helmut Marko.
"It goes like hell," Marko said, observing that five of the top ten runners on the grid have an Italian-made engine.
Mercedes' Toto Wolff admitted: "Yes, we are lacking top speed on the straights.
"Whether that's due to downforce or power, we have to find out, but this was a sobering experience."
Indeed, the gap from Charles Leclerc's first ever pole and the fastest Mercedes was three full tenths.
"They were pulling some serious speeds on the straights," agreed reigning world champion Lewis Hamilton.
One theory is that Ferrari struggled with cooling in Australia but solved that problem for Bahrain.
"I've seen a lot of speculation and I think what I've read is not quite true," said team boss Mattia Binotto. "I can assure you that we have no problems with cooling."
Vettel admitted that his new and young teammate Leclerc simply drove better than him in Bahrain, which raises the question of how Ferrari will handle Sunday's race.
"If you ask me, I will do absolutely everything to keep my first place," said Leclerc.
Binotto said there is "no doubt" that Leclerc is free to race.
"I just think it's important that our two drivers take no chances by fighting each other," he said.
In Australia, 'team orders' were already issued in favour of nominated number 1 driver Vettel.
Binotto said: "Let's wait for the next races and see if the situation arises and how we then react to it."
