The three-day test, which runs until Friday and is live on Sky Sports F1, is the precursor to next week's season-opening race at the same venue and represents the only chance for teams to truly test their cars and fine-tune set-ups ahead of the record 24-race season.

World champion Max Verstappen set the quickest lap of the opening session of 1:32.548 in a new Red Bull RB20 that has caught the attention due to the layout of its sidepods and cooling inlets.

Having already set tongues wagging with the version of the car revealed at the team's launch last week, the first look at the RB20 on track confirmed a change in the cooling inlets around the sidepod in a change of direction from Red Bull's dominant cars of the past two seasons.

• Follow live updates from F1 testing
• When to watch Bahrain testing live on Sky Sports F1
• Stream F1 Testing and more with NOW | Get Sky Sports

Verstappen completed 66 laps during the morning, although it was Fernando Alonso in the new Aston Martin who topped the morning's lap count after an impressive 77 in his 2024 challenger.

Charles Leclerc was second quickest on the timesheet, 0.7s back on Verstappen's early benchmark, after 64 laps with Alonso third and Oscar Piastri in the new McLaren fourth.

McLaren initially had a quiet start to the day with the MCL38 but racked up plenty of laps themselves as the morning wore on.

George Russell, meanwhile, was sixth quickest in a new-look Mercedes W15 which itself has caught attention due to its innovative front-wing design as the former champions bid to take a big step forward in performance this year.

"Hats off to their aero team for this piece of magic on the front wing," said Sky Sports F1's Ted Kravitz. "It's a lovely idea and one of many on this new W15.

"What's also true of Red Bull is also true of Mercedes. Had they just developed what was an okay car that would have been alright, but they had to find a second per lap.

"That's the big question for me: is this new Mercedes a second a lap quicker than last year's Mercedes?

"Is this new wing going to work? Are the rest of the ideas going to work as well? That we will need to find out."

The opening morning of 2024 saw all teams run consistently on track but Williams ran into an unspecified problem in the session's closing 30 minutes when Alex Albon had to pull off track.

More to follow...

Sky Sports F1's pre-season testing schedule

Wednesday February 21 - Day One

• 11.55am-4.05pm: Afternoon Session
• 8pm: Testing Wrap
• 8.30pm: Ted's Testing Notebook

Thursday February 22 - Day Two

• 6.50am-11.05am: Morning Session
• 11.55am-4.05pm: Afternoon Session
• 8pm: Testing Wrap
• 8.30pm: Ted's Testing Notebook

Friday February 23 - Day Three

• 6.50am-11.05am: Morning Session
• 11.55am-4.05pm: Afternoon Session
• 8pm: Testing Wrap
• 8.30pm: Ted's Testing Notebook
• 9pm: Development Corner

When is the first F1 race?

Just one week after testing, the opening race of the 2024 season will begin with the Bahrain Grand Prix from February 29 to March 2.

Due to the Muslim holy period of Ramadan, the Bahrain and, seven days later, the Saudi Arabian Grand Prix, will be held on a Saturday.

This means practice one and two will take place on Thursdays, with final practice and qualifying on Fridays.

Get Sky Sports on WhatsApp!

You can now start receiving messages and alerts for the latest breaking sports news, analysis, in-depth features and videos from our dedicated WhatsApp channel!

Find out more here...

Watch pre-season testing live and then every round of the new season, starting with the Bahrain Grand Prix from February 29-March 2. Stream every F1 race and more with a NOW Sports Month Membership