Ferrari has revealed a potentially more significant Formula 1 upgrade than its drivers let on ahead of the United States Grand Prix.
This was anticipated to be an important package but both Lewis Hamilton and Charles Leclerc played down the step forward that was anticipated from the latest developments being added to its car for this weekend's race at the Circuit of the Americas.
Hamilton said on Thursday: "We have a very, very small upgrade this weekend. It's less than a tenth. It's like half a tenth."
However, in the official FIA submission where each team has to declare what it has brought, the Ferrari changes are quite extensive in performance critical areas.
They include an updated board brace layout, and a redesigned front floor leading edge, as well as a reshaping of both inboard vertical and horizontal board elements.
Furthermore, the shape of the sidepod inlet and undercut has been altered to help airflow better interact with the floor below.
On top of this, Ferrari has a revised diffuser volume, with new fence loading and trailing edge outboard furniture.
The team said the updates are focused on increasing floor downforce at both the front and rear of the car, as well as increasing energy levels and flow stability towards the back.
McLaren updates brake ducts and diffuser
McLaren has brought further upgrades to its car at Austin, with brake-duct revisions at the front and rear to help improve flow conditioning and increase downforce.
The team has also tweaked its diffuser geometry to improve airflow and increase downforce across the speed range.
Red Bull adds a front wing vane
Red Bull has made a minor revision to its front wing, adding a new vane to help with the monitoring of its front tyre temperatures. This is for evaluation purposes so far.
Racing Bulls's step
Racing Bulls has also used the US GP weekend to introduce a hefty update package as it bids to secure its best-of-the-rest status behind the top-four teams.
Its changes include a new front wing endplate, new rear wing flaps and a number of enhancements across the floor edges, the leading edge and the floorboards (formerly bargeboards), all aimed at improving downforce.
Racing Bulls has also reprofiled its engine cover with a new shoulder and uncut.
Other teams' changes
Audi has made revisions to its front brake duct as well as introducing new floorboard geometry to improve local flow conditioning. It will also be running a new mirror stay.
Alpine has reprofiled the second- and third-element flaps of its rear wing to improve airflow conditioning, and has redesigned its rear floor corner to help increase downforce.
Cadillac has updated its forward floor geometry and tweaked the cooling louvres on its sidepods.