It was no real shock to see Mercedes fastest in the first four-day pre-season test at the Circuit de Barcelona-Catalunya. Valtteri Bottas' lap of 1:19.705s on Wednesday was a clear statement of intent from the team for the 2017 season.
But the big surprise was just how close Ferrari was able to run them. Sebastian Vettel's best time was just a quarter of a second back, even though he was running soft compounds compared to ultrasofts for Bottas.
"Ferrari is really fast," Mercedes boss Toto Wolff admitted to Osterreich newspaper on Friday.
But Wolff added that it was still far too soon to really tell how the teams compared with one another.
"Since we have these new rules, the teams are just trying to get a lot of mileage to know their cars," he said.
"At Red Bull, we probably haven't seen the car that will be in Melbourne."
McLaren racing director Eric Boullier also admitted that Ferrari's strong showing last week had been "surprising".
"We did not expect to see them on the pace with the Mercedes. Red Bull seems a little behind, but we do not have all of the information to judge," Boullier told France's Auto Hebdo magazine.
Vettel's team mate Kimi Raikkonen was fastest on Thursday, which was largely given over to wet weather testing. The 2007 world champion didn't seen at all startled by topping the timing screens for the day.
"Nothing surprised me here," Raikkonen is quoted as telling Het Laatste Nieuws. "And I think everything is still within reach for us."
GALLERY: F1 drivers' wives and girlfriends
Keep up to date with all the F1 news via Facebook and Twitter
