The FIA has intercepted yet another potential route that F1 engine manufacturers could have exploited in 2026 so far as the all-new technical regulations are concerned.
F1 teams capitalising on grey areas is a tale as old as time. However, this is the second time in a few days that the new power unit specifications have come under further scrutiny over legality concerns.
While the FIA has yet to single out any specific manufacturer(s) in an official capacity, reports have recently surfaced suggesting that Mercedes and Red Bull have found an ingenious way to exploit thermal expansion and bypass the 16:1 compression ratio limit for the 2026 engines under race conditions. The capacity to effectively retain higher compression ratios would deliver extra performance and better fuel efficiency, translating to a potential gain worth a couple of tenths per lap.
According to the French newspaper L’Équipe, the sport’s supreme governing body is holding a somewhat urgent meeting with the F1 power unit manufacturers on Monday to discuss the loophole and the nature of the advantage Mercedes and Red Bull have allegedly gained.
As the aforementioned controversy still rages on, a fresh amendment to the technical regulations has demonstrated that the FIA is keen to close off any wiggle room left for ambiguity and possible infractions.
Fuel-flow meter and imposition of new limits in 2026
A complete overhaul of F1’s regulatory framework in 2026 will herald a new era with a remarkable 300% increase in battery power and an even split between internal combustion engine and electric power. Additionally, the FIA has mandated the use of advanced sustainable fuels.
The second development in question, which The Race has shed more light on, pertains to the new fuel-flow meter limits as F1 switches to fully sustainable fuels in the upcoming season.
A fuel energy flow limit of 3000 MJ/h will substitute the previous ceiling, which measured a maximum mass flow of 100 kg/h.
This significant revision marks the introduction of a new way of compliance checks, with a single standard unit from the company Allengra replacing the previous use of two fuel-flow meters—one for teams and a control one for the FIA.
All 2026 F1 cars will be fitted with Allengra’s ultrasonic flow meter, and the data it produces will be accessible to both the FIA and the teams.
How the FIA has closed a second loophole
Although the FIA’s attempt at standardisation might appear unexceptional on the surface, the concern stems from the F1 teams potentially altering the temperature of the fuel-flow meter. Manipulating the temperature could theoretically alter the fuel composition or impact the measurement accuracy, providing certain on-track advantages.
Originally, the relevant clause stated that “intentional heating or chilling of the fuel-flow meter is forbidden.”
However, following the most recent World Motor Sport Council meeting that took place on December 10, the previous wording has been replaced with more comprehensive language: “Any device, system, or procedure, the purpose of which is to change the temperature of the fuel-flow meter is forbidden.”
The more expansive phrasing clearly aims to cut off any avenues that could’ve still enabled manufacturers to manipulate the temperature of the fuel-flow meters without it being classified as ‘intentional’ interference.
While the tightening of the 2026 technical regulations doesn’t necessarily suggest that F1 teams were actively trying to exploit another grey area, it alludes to the FIA adopting preventive measures to reinforce their credibility and shield themselves from any further controversies.
