FIA Closes Another 2026 F1 Loophole Amid Red Bull and Mercedes Engine Controversy
The FIA has taken further steps to tighten the 2026 Formula One power unit regulations, reportedly shutting down yet another potential loophole following concerns involving Red Bull and Mercedes. With the new engine rules drawing closer, the governing body remains on high alert as manufacturers continue to explore every possible grey area within the regulations.
The latest intervention comes after allegations that Red Bull and Mercedes had identified a clever workaround relating to the geometric compression ratio of the internal combustion engine. Under the current regulations, engines operate at a compression ratio of 18:1, but this figure is set to be reduced to 16:1 when the new 2026 power units are introduced.
According to reports, the two teams were accused of uncovering a method that would allow their engines to comply with the 16:1 limit when measured statically, while effectively increasing the ratio back towards 18:1 during on-track running. This theoretical advantage was estimated to be worth as much as 15 brake horsepower — a substantial gain that could translate into meaningful lap-time improvements.
The rumours immediately raised alarm bells among rival manufacturers. Audi, Honda and Ferrari are understood to have urged the FIA to ensure the regulations were interpreted in a way that prevented any such manipulation. The governing body subsequently clarified the rules to ensure that any variable or dynamic changes to the compression ratio would be strictly prohibited.
Now, the FIA has reportedly identified another area of concern within the 2026 power unit framework — this time involving the fuel-flow meter.
New Fuel-Flow Rules Under the Spotlight
From 2026 onwards, Formula One will undergo a fundamental shift in how fuel usage is regulated, driven by the introduction of fully sustainable fuels. The current system, which limits fuel mass flow to a maximum of 100 kilograms per hour, will be replaced by an energy-based restriction.
Under the new rules, fuel usage will be capped at a maximum energy flow of 3000 megajoules per hour. This change is designed to reflect the varying energy densities of sustainable fuels and ensure a level playing field across manufacturers.
Another major adjustment is the hardware itself. The existing setup, which uses two fuel-flow meters, will be replaced by a single standardised unit. This device will be mandatory across all teams and will transmit real-time data to both the FIA and the competitors, increasing transparency and oversight.
However, despite these safeguards, the FIA believes the revised regulations left room for exploitation — particularly regarding the temperature of the fuel-flow meter.
Temperature Manipulation Concerns
The concern centres on the possibility that teams could gain an advantage by influencing the temperature of the fuel-flow meter. Changes in temperature can affect fuel density and energy calculations, potentially allowing teams to alter either the fuel composition being measured or the accuracy of the readings themselves.
In the original wording of the regulations, teams were prohibited from “any intentional heating or chilling of the fuel-flow meter.” While this may have seemed clear, the inclusion of the word “intentional” left a potential loophole.
Teams could theoretically argue that any temperature variation was unintentional — a side effect of packaging, cooling layouts, or operational conditions — rather than a deliberate attempt to manipulate the system.
To eliminate this ambiguity, the FIA has revised the language of the rule. The updated version now states:
“Any device, system, or procedure, the purpose of which is to change the temperature of the fuel-flow meter, is forbidden.”
By removing the word “intentional,” the FIA has closed off any possible defence based on accidental or indirect temperature changes. The revised wording ensures that responsibility lies squarely with the teams to demonstrate that no aspect of their design or operation affects the fuel-flow meter’s temperature.
A Preventative Move, Not an Accusation
Importantly, there is no evidence to suggest that any team had already begun exploiting this loophole. Instead, the FIA’s action appears to be a preventative measure aimed at avoiding future disputes similar to those seen in previous regulatory eras.
As Formula One prepares for one of the biggest technical overhauls in its history, the governing body is determined to ensure that innovation does not cross the line into exploitation. With engine performance expected to be tightly matched under the 2026 rules, even marginal gains could prove decisive.
The FIA’s swift response underscores its commitment to maintaining fairness and regulatory clarity as manufacturers push the limits of engineering ingenuity. With further scrutiny likely in the coming months, teams will be forced to focus on performance within the spirit — not just the letter — of the rules.
