But Vettel and Ferrari had initially been in scintillating form in pre-season, regularly running the fastest auto in testing at the Circuit de Catalunya in Barcelona. Halfway through the final day of testing Lewis Hamilton was asked what sort of advantage Ferrari had over the rest of the teams.
The five-time world champion relishes a field with greater competition, but said the richer teams' ability to develop quicker could maintain F1's status quo.
Lewis Hamilton says he is braced for his "toughest battle yet" after conceding Ferrari have had the best auto in pre-season testing. Over the next week we will try to gain another tenth at least in our understanding of the vehicle.
"Behind us, I don't know which team is fourth but they're a lot closer". "Today, it was nice to feel the vehicle on lighter fuel and to discover it a little better; I really enjoyed the day and got a good feel for the tyres as well". Or are they more turned-up than us or are they just more efficient and just have less drag than us in general? Valtteri Bottas was second quickest on a 1'16.561 which is over a second quicker than anything the team had done in testing until today.
Lewis Hamilton said that he enjoyed his runs on low fuel as Mercedes AMG Petronas showed its potential pace on the final day of 2019 Formula 1 winter testing. "We've used our time on track here in Barcelona efficiently, learning a lot and improving our performance over the past two weeks".
"The last couple of days have been very positive", said Hamilton. This is going to be the toughest battle yet. Last year they arrived here with a vehicle that was working well, but they've got even better this year. "We've got a hill to climb, but we know how to do it".
"It would be completely wrong to think today that we're faster than them", he insisted. "We did our homework between the two tests which is important, and that resulted in the auto being comfortable to drive by the end of the second week".
"Of course, naturally we hope that it's definitely not bigger than what we might see now - we hope that it's better, but we can't bank on that".
A gearbox problem caused Max Verstappen's final day on the track to end early. But, overall, the Red Bull driver is confident about the upcoming season. "So I think there is still much to do and the season has not started yet".
Hamilton believes that Ferrari started working on their 2019 auto when they realised that they were unlikely to win the 2018 championship.
"I've no reason to expect that to come down".