Post-Japanese Grand Prix, Lewis Hamilton hinted at a “deficit” between his car and Charles Leclerc’s, saying that something on his side was “underperforming”.

While he wouldn’t reveal what this was, it’s thought to relate to the setup differences between the cars with Hamilton’s preference for a lower, stiffer ride height exposing the SF-25’s inherent difficulties in this area.

Ahead of these upgrades however, Hamilton felt that the ‘deficit’ “should be gone” as a result of the new floor – so what changes have they made?

Of course most of the changes are under the car, which can’t be seen, but their submission document mentions “reoptimisation” of the boat and tunnel expansion.

The front of the floor has also been reprofiled alongside some fairly significant work on the inner and outer floor fences. Whereas the outer fences used to have a few steps down, there is now just one larger one with an inset set of smaller steps.

Further along the floor edge, the furled up scroll section has been increased in length, height and has additional strakes.

The team’s submission document says these changes are to improve the “losses travelling downstream” and as such they’ve introduced a redesigned diffuser expansion and updated a pillar winglet on the rear wing aiming at minor improvements to the car’s aerodynamic efficiency.

Hamilton ran these upgrades first during the unrepresentative Free Practice 1, with Leclerc also receiving the new parts for Free Practice 2 as he was swapped out for rookie Dino Beganovic for the first session.

In this second session however, the drivers were further off the single lap pace – Hamilton ranked P8, 1.071s off Piastri out front, with Leclerc slightly further up the order in P4 but still over five tenths off the benchmark time (+0.540s). Despite this, Hamilton said the upgrade had “worked” and now it was about finding consistency.

While there may be no immediate or dramatic improvements in lap time, this is in line with the expectations of the upgrades set by Ferrari’s deputy team principal Jerome d’Ambrosio.

“It’s just as simple as hopefully we’ve added a little bit of downforce, kept a good drivability, and added a bit of performance on the car,” he said.

“Our expectations are not that this is going to revolutionise the whole performance picture.”

Instead, the hope is to take a “step forward” by adding “marginal and steady gains”.