Ferrari have pushed as hard as possible to develop the SF16-H ahead of the first race, and an engine upgrade in Melbourne brings their engine token spend thus far to 23 out of their allocation of 32, with no areas being blacklisted this season in order to enable those who are behind to try and catch up.
Mercedes, by contrast, have used only 19, Honda 18, and Renault only seven following their heavy late-season work last year.
“I think this year that the whole pack looks like it’s a little bit closer, but personally I think that they’ve got something up their sleeve this weekend,” said Hamilton of his Italian rivals.
“I think Ferrari are going to be a lot closer than they talk about, than just arriving on a low but going on to deliver high.
“Do I welcome that? Absolutely!”
Vettel, meanwhile, said that he thought Ferrari have done enough to trouble Mercedes in 2016, but that he was not yet sure when.
“Obviously the project of this year’s car started very early so I think it is definitely a big step forward overall,” stated the German. “Obviously from the outside it’s easy to see the main differences but I think especially on the inside we’ve done a very, very nice job and it allows us to be, first of all, quicker from the start and also have more chance of improving throughout the year.
"So that’s good news. Whether it’s good news right from the start, I don’t know.”
There’s another little factor that may just work in Ferrari’s favour this weekend. With Mercedes sticking almost exclusively to the medium Pirelli tyres in testing, and with heavy rain expected at Albert Park on Friday, there’s an outside chance that Hamilton and team mate Nico Rosberg could actually go into the race with no further experience here of running the softs; and should neither qualify in the top eight, they could be running the supersofts in the race for the first time in 2016.