The FIA reduced the maximum compression ratio to 16:1 for 2026, a measure to control costs. However, the standard is measured cold. Mercedes and Red Bull have identified this loophole and use additive manufacturing to create pistons that, with the heat of combustion, expand strategically. The goal is to increase the real compression on track, gaining power. Other manufacturers like Ferrari have already requested clarifications from the FIA.
Thermal design through complex internal structures 🔬
3D printing allows internal geometries impossible to achieve with forging. These pistons incorporate structures that direct the combustion heat flow to specific areas. By heating non-uniformly, the metal expands in a controlled manner, modifying the chamber volume under operating conditions. This raises the effective compression ratio above the regulatory limit measured cold, without violating the letter of the regulations.
The FIA measures in a fridge, the engines run in hell 🔥
It seems the FIA wrote the regulations thinking of engines that run at fridge temperature. While they measure with calipers in a lab, Red Bull and Mercedes engineers have designed pistons that grow strategically when in the hell of combustion. It's a classic case of following the letter of the law, but not its spirit. The other teams, of course, don't ask to change the pistons, but for the FIA to use a thermometer.