The FIA was pushed for numerous clarifications and Ferrari had to vigorously defend its position, as fellow competitors questioned the legality of its power unit throughout the season.
The situation is still not over as rival teams remaining unhappy about a secret agreement reached between Ferrari and the FIA over what it is up to.
With rivals unable to understand how Ferrari was able to achieve this boost, numerous theories were thrown out there: ranging from questions over whether it was using a controlled leak of oil from the intercooler to improve combustion, to suggestions it had found a way around the fuel flow limit.
Here we look at both those theories, how they could be applied and also take a look at how changes in the regulations have been made to ensure teams are not cleverly exploiting these areas in the future.
Oil burning practices have been a staple of the hybrid era, as the various fuel and lubricants manufacturers have worked closely with their engine partners to get more performance from their products.
The 100kg/h fuel flow limit puts an onus on getting as much performance as is possible from the fuel. Plus, with the regulations surrounding the chemical composition of fuel being far more restrictive than oil, it is obvious that other avenues have been looked at to boost performance.
Burning oil as fuel became a natural playground, as the regulations surrounding the quantities and delivery methods were relatively weak. The FIA set about reining in the team's efforts to use these processes over the years, controlling the specific quantity and methods for how oil can be burnt.
But, that's not to say that there were not other ways of doing it.
Ferrari SF70H 2017 engine
The use of fuel additives within the oil clearly raised questions amongst the engineers about how you could continue to add combustion boosting elements into the fuel mixture without being reliant on oil vapour as a delivery mechanism.
As such, theories surfaced among the non-Ferrari powered teams that its liquid-to-air cooler was utilising an oil based lubricant as the cooling medium, rather than using a more conventional water based solution.
It was then surmised that this additive rich lubricant could be leaked into the boost tract and provide the necessary combustion improvement that was leading to the Scuderia's straight line boost.
In full flow
Fuel flow meter
Learning from F1's turbocharged past, the FIA needed a way to contain the boost levels at which the power units could be run. Rather than meter the boost pressure, as was done during the last turbocharged era, the FIA opted to meter fuel delivery.
Housed, within the fuel tank, the meter had to be more accurate than anything that was already available in the marketplace. It had to tolerate the range of conditions it would be placed under, provide the necessary accuracy and offer result repeatability over all devices in use.
The current meter, supplied by Senstronics since 2018, uses the time-of-flight principle, whereby transducers at either end of the meter fire short bursts of ultrasound in opposing directions. These values are measured and scaled according to the known dimensions of the flow tube to give the volumetric flow rate.
To get the necessary accuracy the meter measures the flow rate over 2200 times per second and is manufactured from a single metallic material to eliminate the need for any further calibration for different thermal expansion rates.
How does one defeat a flow meter then?
Whilst the meter takes measurements at up to 2200 times per second, this is filtered and the FIA works with a much smaller sample, as it must remove some of the noise created by various external variables.
This is supposed to give a more accurate reading of the flow rate, but it has been proposed that it could also be used as a way of defeating the process.
The introduction of noise (or resonance) at a certain frequency or even one similar to the metal that the meter is made from could, for example, create a dissonance.
This was the basis for Red Bull's most recent probe into Ferrari's straight line speed advantage and 'signal filtering', as it asked the FIA for clarification on the matter.
The FIA responded with a technical directive, making clear that the three scenarios offered by Red Bull would be in breach of articles 5.10.3 and 5.10.5 of the technical regulations.
Reading between the lines…
Shell oil and fuel testing unit
A good way of spotting where the FIA have had problems in a previous year is amendments made to the wording of the technical regulations.
For 2020, several lines have been added to Article 19.8 - Sampling and testing at an Event. All of these changes relate to the fuel samples given to the FIA for analysis purposes, their relationship with the fuel in use.
For the sake of clarity, teams can approve five fuel formulations per season but are only allowed to use two per event.
Perhaps the most pertinent article is the final paragraph of 19.8.4:
If the deviations observed (above) by GC [gas chromatography] indicate that they are due to incidental mixing with another Formula One fuel to the one declared, but which has been approved by the FIA for use by the team, the fuel sample will be deemed to comply, provided that the adulterant fuel is present at no more than 10% in the sample. Any systematic abuse of mixed fuels will be deemed not to comply.
Of course there's always some room for cross contamination when changing between fuels, and that's why the FIA have allowed some wiggle room. But, these alterations suggest that a team, not necessarily Ferrari, was intentionally gaming the sampling system and mixing the two fuels that they were allowed to use at a given event.
Having the foresight to intentionally use two different fuel formulations raises some important questions about the composition and interaction of both fuel formulations.
Whilst there are heavy restrictions on what can be added to the fuel, which requires the suppliers to carefully balance their formulations, heavily weighting one of these with combustion boosting elements would not only have an interesting impact on combustion, but also in terms of how that might create a dissonance with the fuel flow meter readings...
Are two better than one?
It's clear that the FIA has made several attempts to cover off numerous aspects of the regulations that might have allowed for enhanced combustion or permitted the fuel flow limit to be exceeded, if only temporarily.
However, a technical directive (TD/042-19) issued toward the end of the season will be an important factor in policing fuel flow going forwards.
Up until this point the information gathered by the fuel flow meter has been sent to the SECU (Standard ECU) and has been accessible by both the teams and FIA.
To help police the fuel flow restrictions, the FIA has instructed teams that a secondary meter must be installed in series. This meter incorporates new, more robust anti-aliasing techniques, randomizing when the measurements are taken to prevent external feedback being able to match the measurement frequency.
This data is also sent via a separate encrypted data connection to the FIA SDR (Security Data Recorder), making it inaccessible to the teams.
To further randomise the process the FIA will be handed a pool of flow meters by each team and they will allocate a meter to each car at the start of an event and retrieve it at the end.