Admitting after pre-season testing that the RB21 was not the fastest car on the grid, Red Bull have made 17 changes to the car ahead of the season-opening Australian Grand Prix.

Although Max Verstappen enters the new season as the defending World Championship, the Dutchman chasing his fifth title on the trot, Red Bull are not the favourites.

From front to rear, 17 new parts for Red Bull’s RB21

According to the data crunchers, pre-season’s pecking order had McLaren as the team to beat with Helmut Marko, saying their advantage could be as much as “two to three-tenths” per lap. Red Bull were in the bunch behind with Ferrari and Mercedes.

“The car did not respond how we wanted at times, but it is going in the right direction, just maybe the magnitude of the direction was not as big as we expected and it’s something we need to work on for the first race and future development,” admitted Red Bull’s technical director Pierre Waché.

And work on it they did, Red Bull changing a staggering 17 parts ahead of Melbourne.

Front wing, nose, front suspension, floor body, floor fences, floor edge, engine cover, cooling louvres, rear suspension, beam wing, rear wing and rear wing endplate.

15 of the updates are performance related with the other two reliability and cooling.

As for their main rivals, McLaren have brought a new front corner and beam wing, revising the brake duct winglet for performance, while Ferrari’s switch from a pushrod to pullrod has been confirmed. The Scuderia have also revised the SF-25’s engine cover for ‘improved interactions with the floor / floor edge as well as the rear end of the car ‘

Mercedes have a new sidepod inlet, floor body, engine cover, beam wing, front suspension, and rear wing, all performance-based updates to improve flow to either the floor or the rear of the W16.

Aston Martin and Haas also went big with 12 and 13 new parts with Alpine, Racing Bulls, Williams and Sauber also introducing changes.

Read next: Red Bull go ‘all-in’ with RB21 updates for Australian GP opener