Are Ferrari ahead of Mercedes? By how much? And where do Red Bull fit in? Watch a round-up of the big testing stories.
Ferrari's Sebastian Vettel and Mercedes' Lewis Hamilton finished neck-and-neck on the final F1 Testing timesheet at Barcelona.
The final numbers and your essential port of call for the quickest laps in testing by driver and team, plus laps completed.
Ferrari continue to turn heads at F1 Testing, with Charles Leclerc setting by far the fastest time of the winter on Thursday.
Charles Leclerc posted by far the quickest times of Winter Testing so far for Ferrari, while Pierre Gasly crashed the Red Bull.
Carlos Sainz is impressed by McLaren's progress at F1 Testing after the team set an eye-catching pace to once again top the timesheets.
Ferrari suffered their first major setback of F1's winter with a costly crash on Day Two, while McLaren set the fastest time of Testing.
Lando Norris set the pace for McLaren despite two track stoppages, while Mercedes and Ferrari also ran into delays, at Barcelona.
Lewis Hamilton has revealed how rule changes and a varied winter fitness regime have put him in the "best shape" of his career.
Charles Leclerc hopes he is competitive enough against Sebastian Vettel to give Ferrari a welcome "problem" this year.
Reviewing an intriguing four days of action at Barcelona as Ferrari make the early waves, while Red Bull enjoy first week with Honda.
Renault's Nico Hulkenberg set the fastest time of F1 Testing so far as the first week at Barcelona came to an intriguing close.
Daniil Kvyat was the pace-setter on an unpredictable third day of F1 Testing as Toro Rosso led a surprise top three on the timesheets.
Williams admit their start to the F1 2019 season has been "horrible" but are optimistic they can make up for lost time at pre-season testing.
Ferrari continued their fast start to F1 2019 at pre-season testing as Charles Leclerc topped the timesheets on Day Two.
Sebastian Vettel topped the timesheets as Ferrari made an impressively fast start to F1 2019 on the first day of pre-season testing.
Toto Wolff says Lewis Hamilton is in the best physical and mental state he has seen ahead of Mercedes' 2019 history quest.
Watch the essential review from Test One in Barcelona as Sky F1's Mark Hughes, James Galloway and Craig Slater discuss the key talking points.
Mercedes' late show gives pacesetters Ferrari food for thought, while the midfield pack looks to be closer than ever.
©2019 Sky UK