Formula 1 testing: Lewis Hamilton says Ferrari 'bluffing' after Sebastian Vettel's fastest lap
Lewis Hamilton believes Ferrari are "very close" to Mercedes after Sebastian Vettel set the fastest time of pre-season testing.
In Barcelona, Vettel beat Mercedes' previous benchmark by 0.286 seconds but said Mercedes remained favourites going into the first race in Australia on 24-26 March.
But Hamilton said: "I think Ferrari are bluffing and that they are a lot quicker than they are showing.
"They are very close, if not faster."
He added: "It's difficult right now to say who is quicker."
Vettel's time on Thursday of one minute 19.024 seconds beat the previous best of the seven days of testing, set by Hamilton's Mercedes team-mate Valtteri Bottas. Friday is the final day of on-track preparation before the cars fly to Melbourne.
Vettel said: "If you look at the amount of laps Mercedes has done, at how slow they go in testing historically, how much they can ramp it up for races, it's clear.
"They're very fast if you look at their long-run pace. They're the ones to beat."
Vettel, who set his quickest lap on the "ultra-soft" tyre while apparently lifting off briefly before completing the lap to disguise his full pace, was also impressive in being just 0.3secs slower on the "soft".
The "ultra-soft" is said to be about 1.2secs faster than the soft tyre.
Hamilton was second fastest, 0.328secs behind Vettel, also using the ultra-soft.
Is Ferrari's pace real?
It would be unwise to read too much into Vettel's pace at this stage - pre-season testing times are notoriously unreliable indications of real form because it is impossible to know the details of a number of influential variables, such as fuel load and engine mode.
But it continues the impression that Ferrari may be in better shape heading into this season than they have been for some time.
The team failed to win a race last season - for the second time in three years - and restructured the team internally over the second part of 2016 in the hope of being in better shape for this season.
"The car is much better than last year because the nature of the formula has changed," Vettel said, referring to new rules this year that have made the cars faster and more demanding.
"So far things are making sense - but it's still early days.
"You need to look at more than one single lap time. We still have a lot of work to do. The team is working very hard.
"Last year's experience has in many ways helped us to grow as a team. Hopefully we can carry that into this year. We are starting to grow together more and more.
"If you win three titles in a row it is clear who is the favourites, rule change or not. Mercedes have good people and a working team. They are the ones to beat."
Red Bull's Daniel Ricciardo appeared impressed by Ferrari's performance.
"Ferrari looks strong," he said. "At the moment they look like they are pretty close to Mercedes' pace if not on it - so it is going to make Melbourne interesting, and I think we will get there."
Problems for McLaren go on and on
Meanwhile, McLaren-Honda continue to struggle, a day after their lead driver Fernando Alonso said the Honda engine had "no power and no reliability".
The Spaniard's team-mate Stoffel Vandoorne set the team's fastest time of the winter on Thursday morning - 2.3secs slower than Vettel. But the car broke down on track shortly before the end of the morning session.
Unlike previous problems, Vandoorne was able to return to the track not long afterwards - only to break down again straight away.
For the second day in succession, McLaren were the only team not to complete even 50 laps. Mercedes and Ferrari both achieved three times as much.
The team cancelled a media briefing that had been planned for the lunch break with racing director Eric Boullier and Honda F1 chief Yusuke Hasegawa.
The Japanese then flew back to Honda's base in Sakura to oversee development of a modified engine aimed at solving the problems suffered in testing before the first race of the season in Australia on 24-26 March.
There were also continuing problems for the Renault and Toro Rosso teams, who have both had difficult pre-seasons with reliability, if not to the same extent as McLaren-Honda.
Fastest times, day three, final pre-season test
1 Sebastian Vettel (Ger) Ferrari 1:19.024 ***
2 Lewis Hamilton (GB) Mercedes 1:19.352 ***
3 Esteban Ocon (Fra) Force India 1:20.161 ***
4 Daniil Kvyat (Rus) Toro Rosso 1:20.416 **
5 Kevin Magnussen (Den) Haas 1:20.504 ***
6 Daniel Ricciardo (Aus) Red Bull 1:20.824 *
7 Stoffel Vandoorne (Bel) McLaren 1:21.348 ***
8 Valtteri Bottas (Fin) Mercedes 1:22.038 *
9 Jolyon Palmer (GB) Renault 1:22.418 *
10 Pascal Wehrlein (Ger) Sauber 1:23.208 *
11 Marcus Ericsson (Swe) Sauber 1:23.330 *
12 Felipe Massa (Brz) Williams 1:24.443
13 Lance Stroll (Can) Williams 1:24.863 *
*** = ultra-soft tyre; ** = super-soft; * = soft; others on medium