F1 engineers float theory that Mercedes’ 2026 trick isn’t permitted by FIA

Mercedes may have landed themselves in the middle of a controversy to start the new Formula 1 regulations.

Fans did not get a clear sense of who was fastest at the Barcelona shakedown, but there were early indications that Mercedes could be setting the pace.

No other team managed to complete more than 500 laps, and while most were still gathering data on day five, Toto Wolff’s side had already packed up and left.

There was quiet confidence within the Silver Arrows camp during their team launch, with Wolff addressing questions about their power unit straight away.

A compression trick Mercedes are believed to have discovered could give George Russell and Andrea Kimi Antonelli an edge over their competitors.

F1 Engineers Link Mercedes’ 2026 Engine to New Piston Theory

A recent report from AMuS has shed some light on what Mercedes might be up to as they get ready for the new season.

According to the report, Mercedes are using 3D-printed pistons designed to boost the engine’s compression ratio.

Some engineers believe this setup would only push the ratio up to 17:1, falling short of the 18:1 mark that’s been widely rumoured.

There’s now a theory floating around that Mercedes have added a small pocket near the top of the cylinder inside their combustion chamber.

The thinking goes that during FIA static tests, this pocket fills up, allowing Mercedes to meet regulations. But under race conditions, when things heat up and pressure builds, a thin channel connecting to the pocket is said to close off, raising the compression ratio.

This idea has come from other teams in Formula 1. According to reports, an inquiry was sent over to the FIA and came back with news that this particular method would not be allowed if proven true.

Right now there’s no concrete evidence linking Mercedes directly to this method. However, teams around the paddock are clearly interested in how they’ve managed any potential gains with their power unit heading into 2026.

Ferrari planning counter move to Mercedes’ 2026 F1 power unit innovation

There are five different engine manufacturers on the grid this year, but Mercedes are expected to have a clear edge over at least three of them right from the start.

Honda, now working exclusively with Aston Martin, have been struggling since their planned exit from F1 following their split with Red Bull.

Meanwhile, both Red Bull Powertrains and Audi are new to the scene. Despite pulling in talent from other teams, they still don’t match Mercedes’ level of experience.

The real competition is expected to come from Ferrari. While their engines showed good reliability during testing in Barcelona, it’s still unclear if they can match Mercedes for pace.

Ferrari are already working on ways to close the gap to Mercedes’ engine development, but whether that will be enough to put Lewis Hamilton and Charles Leclerc in contention remains to be seen.