Haas, AlphaTauri, Aston Martin and Mercedes all have notable upgrade packages at the United States Grand Prix despite the sprint weekend format.

There’s only one practice session for all teams to analyze any new parts, but that hasn’t stopped a whole new car concept being brought by Haas at the start of a tripleheader of race weekends, with the list of updated items consisting of front brake ducts, the floor body, floor edge, sidepod inlets, the engine cover and cooling louvers.

While not as clear visually, AlphaTauri has a similar number of modifications this weekend, with the majority focusing around the floor via a revised floor body, floor edge and floor fences. There’s also a change to the engine cover — with the central bodywork exit tweaks improving cooling — and the rear brake ducts. Perhaps the most notable change from AlphaTauri though relates to the chassis itself, with the team subm itting revised surfaces local to the inboard front suspension.

Aston Martin broke the curfew overnight as it worked on upgrades that include changes to the floor edge in conjunction with the engine cover, diffuser and beam wing to produce increased loading on the floor as an overall package.

As has been the main focal point for most teams during the season, the floor is the only area Mercedes has modified as it tries to understand the direction it is taking for next season. The floor body has a raised leading edge that improves flow to the rear of the car and increases rear downforce, while that is balanced by changes to the forward floor edge flap th at is designed to improve forward floor load.

The only other new part submitted for the USGP is a floor edge modification at Alfa Romeo — a continuation of the major upgrade package it brought to Singapore — while Red Bull, Ferrari, McLaren, Alpine and Williams have no updates this weekend.