Mercedes Rules Out ADUO Engine Upgrade for Now

Mercedes has ruled out using its Additional Development and Upgrade Opportunities (ADUO) token for a Formula 1 power unit upgrade, despite FIA data showing its internal combustion engine trails benchmark Red Bull by at least 2%. Fresh hardware fitted to George Russell and Kimi Antonelli at the Austrian Grand Prix contained only reliability tweaks and the natural gain of lower-mileage units.

Why it matters:

The stance carries weight for the championship and the ADUO framework. While Ferrari and Audi have already used their allocations, Mercedes team principal Toto Wolff is satisfied with the "bit more spiciness" from new components. Yet by not pursuing a performance step, Mercedes effectively blocks Red Bull from unlocking its own ADUO eligibility, as regulations require a rival to surpass Red Bull by 2% before the leaders can access extra development.

The details:

• Wolff confirmed the Austrian Grand Prix power units were replacements, not upgrades, with reliability revisions implemented across the board.
• Battery and control electronics updates targeted failure modes that caused Russell's retirement in Canada and Antonelli's issue in Barcelona.
• The FIA's pre-Canada assessment grants Mercedes extra spending and test bench hours for one new homologation this year and another in 2027.
• Customer teams also introduced the Mercedes battery and control electronics fixes in Austria, with further fresh elements expected over the coming races.
• Red Bull cannot qualify for ADUO until a manufacturer overtakes its benchmark status, leaving it reliant on an FIA review of data from the Monaco-to-Hungary window.

What's next:

Red Bull continues to challenge the pre-Canada benchmark ruling, with team principal Laurent Mekies warning that rivals could exploit the system by freezing ICE progress to permanently deny Red Bull upgrade access. With Mercedes prioritizing reliability over performance and the FIA review dragging into late July, the political standoff over engine parity is poised to escalate beyond the summer break.