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Bahrain GP in Malaysia · Friday's FIA document

Sepang: Mercedes updates its car again, seven parts and its biggest package since Canada

For the team leading the constructors' championship it is a rare package, and it lands in the area where its car is already the best. Friday, though, raised a different question.

Muretto · Redazione tecnica·FIA
The document Seven lines, almost all under the car

On Friday morning, before practice, the FIA published the list of new parts each team is bringing to Sepang. There are 14 lines from 7 of the 11 teams. Almost all are declared as development, only two as set-up for this circuit.

Mercedes alone accounts for 7 of them. All are development. Four concern the floor: the board at the front, the leading edge, the corner and the body, up to the roof and side walls of the diffuser. The other three are at the back: the rear suspension fairings, the winglets around the rear brake drum and the rear bodywork, reduced in volume and given a steeper ramp to push more air towards the floor.

The team gives local load as the reason for four of the parts, and the need to guide the air towards the rear for three. The document states intentions, not effects: it does not contain a single performance figure.

Each team has a row with its name: the bar on the right is the parts declared as development («Performance») and, where there are any, a second «· circuit» row on the left shows those declared as set-up for the circuit («Circuit specific»); the order follows the development bar. These are lines of the document: one shared description can cover more than one. The note on the right says in how many previous 2026 weekends that team had brought updates (this one excluded). Different denominators where the source was unreadable: Williams @ Australian Grand Prix.Who brings what to Sepang: parts declared to the FIA, by teamMalaysia 2026 · FIA document◄ SET-UP (Circuit specific)DEVELOPMENT (Performance) ►Mercedes+711/15 previous weekendsRacing Bulls+112/15 previous weekendsRacing Bulls · circuit−1Alpine+110/15 previous weekendsFerrari+112/15 previous weekendsHaas+112/15 previous weekendsRed Bull+114/15 previous weekendsMcLaren=13/15 previous weekendsMcLaren · circuit−1Aston Martin=no updates declared · 6/15 previous weekendsAudi=no updates declared · 9/15 previous weekendsCadillac=no updates declared · 13/15 previous weekendsWilliams=no updates declared · 10/14 previous weekendslines of the document, not the size or number of updates · the notes do not share one denominator: see provenance
Each team has a row with its name: the bar on the right is the parts declared as development («Performance») and, where there are any, a second «· circuit» row on the left shows those declared as set-up for the circuit («Circuit specific»); the order follows the development bar. These are lines of the document: one shared description can cover more than one. The note on the right says in how many previous 2026 weekends that team had brought updates (this one excluded). Different denominators where the source was unreadable: Williams @ Australian Grand Prix.
The season The biggest package since Canada

Read one after another, the FIA documents of 2026 show that seven lines are not Mercedes' usual rhythm. In the 15 previous weekends it had declared 29 in total. In Baku it had declared none.

The last time it brought at least seven was in Canada, at the end of May, with eight. Over the same period McLaren and Red Bull had declared 49 each, Ferrari 45.

Before practice, Russell said the step is big precisely because so much time has passed since the last one: it is unusual, he explained, to have an upgrade in May and the next one almost in October. He hopes the package takes Mercedes back to the front at tracks like this one, which have been harder for the team in recent races.

A line, though, is not the size of an update: a new wing and a small change to the edge of a profile take up the same space in the document. The count shows how often and where a team changes its car, not how much the change is worth.

The lines Mercedes declared in the FIA «Car Presentation Submissions» document of each 2026 Grand Prix, in calendar order; Malaysia in solid colour. These are lines, not the size of the updates: a line can be a new wing or a small tweak.Mercedes: lines declared to the FIA, weekend by weekend2026 · calendar orderAustralia3China0Japan0Miami2Canada8Monaco1Spain1Austria2Great Britain0Belgium3Hungary3Netherlands1Italy2Madrid3Azerbaijan0Malaysia7Malaysia in solid colour; lines of the document, not the size of the updates
The lines Mercedes declared in the FIA «Car Presentation Submissions» document of each 2026 Grand Prix, in calendar order; Malaysia in solid colour. These are lines, not the size of the updates: a line can be a new wing or a small tweak.
Downforce Where Mercedes is already strongest

The floor provides the largest share of the aerodynamic load, the share that costs the least drag. This year's technical regulations made it narrower along with the rest of the car: less surface means less load to take, which is why almost every team works on it all year.

A floor part should show up in cornering speed. Across the 13 races of the season in which we measure it, Mercedes is first of the eleven teams: the Sepang package pushes where the car is already strongest. Ferrari, second on the same measure, brings a single part in the same direction: a diffuser change it declares not designed for Sepang, but for the car's whole operating window. Red Bull, fourth, adds a new floor board.

What teams are really after with the floor is load that stays stable as ride height changes. A median cornering speed does not show that.

Friday The others, and what practice said

The rest of the document is mostly about heat and set-up. McLaren brings a new engine cover, declared as set-up for the circuit: it is meant, the team writes, for the high cooling demands of this track and the ones that follow. Racing Bulls uses for balance the longer front-wing flap introduced at the previous race, and changes the rear-wing supports.

Alpine trims the exit of the front brake drum to cool the brakes more, while Haas declares a rear impact structure available on track to tune the car for this circuit, which does not mean it will be fitted. Williams, Aston Martin, Audi and Cadillac declared nothing, and no team states which of its two cars a part goes on.

After practice Andrew Shovlin said the team's concern is race pace, where Mercedes looked unusually off the pace, and Russell linked the problem to tyre overheating and degradation: a set-up question, he said, more than one of the upgrade.

The race is the first measure of the package: cornering speed will show whether the new floor is visible, and the long-run pace whether the tyres matter more this weekend.