Mercedes' Lewis Hamilton says that Ferrari clearly has the upper hand and already holds a big advantage in terms of pace over the rest of the field heading into the first Grand Prix of 2019.
The reigning world champion suggested that the new Ferrari SF90 might have up to half a second per lap more speed than his own W10, based on what he's seen during the eight days of pre-season testing at the Circuit de Barcelona-Catalunya.
“I’m not quite sure, but I think it is potentially half a second," Hamilton told reporters on Friday when asked how much quicker he thought his rivals were. "Something like that, potentially."
But he acknowledged that the estimation was pure guess work at this point.
“We really won’t know [until the start of the season]," he continued. "Everyone will have different power modes and fuel usage, and you don’t know what everyone is doing.
“So Melbourne will be the first time you get a sight of it and then it will be a good four races before you know just where you stand."
He also pointed out that the cars being tested in Spain were not the same as the finished articles that will take to the track on the other side of the world in two weeks' time, and that there was still time to make improvements.
“The car is old now and worn and torn, so we will have new components and all of that stuff will come along," he explained. "It will be interesting.
“We will be analysing a lot from this test and there will be some [modifications] that we will try to implement for the race.
"There is obviously not a lot of time," he admitted. "But over the next week we will try to gain another tenth at least in our understanding of the car."
But Hamilton conceded that if Ferrari really had made the sort of performance gains on show in testing, then he would have his work cut out for him to retain his title in what could prove to be his hardest championship battle to date.
“It doesn’t make it easier, that’s for sure,” he said. “Naturally it makes it harder.
“We weren’t behind anywhere near as much as that I would say last year," he said of the predicted half second deficit. “Already last year there were many, many occasions where we as a team were behind on performance so we had to overachieve on delivery.
"Now we just have to reach even further than we did last year when we were behind.
"That means we have to squeeze our performance even more. But we’re also going to have to be careful in that scenario, because that can push you over the edge and you can have faults.
"We just have to be diligent and stay balanced," he added, pointed out that his team had the experience and confidence to face down whatever challenge Ferrari could throw at them in 2019.