Formula 1 chiefs have approved a plan for a fresh clampdown on oil being illegally burned as fuel in qualifying, after suspicions of the tactic emerged again pre-season.
Red Bull queried the FIA about F1 teams burning oil to deliver a power boost on Saturday afternoons, suspecting Mercedes had benefited the most from this.
In response, the FIA confirmed that such activity was not allowed, and upped its monitoring of oil usage and the chemical composition of oil being used.
Mercedes motorsport boss Toto Wolff suggested Red Bull had "seen ghosts" and his outfit has maintained an advantage in Q3 this year.
Nothing untoward has been found with the increased scrutiny, and three further measures have been approved by the F1 Commission to be added to the 2018 regulations, once ratified by the FIA's World Motor Sport Council.
The first new requirement is that teams must supply the measurement of the oil level in their cars' main tank to the FIA "at all times" during a grand prix weekend.
The mass of the oil in tanks other than the main tank must also be declared to the FIA one hour before the start of the race, to provide a total sum of what is in the car.
This is aimed at highlighting anomalies in oil consumption, such as extra oil being burned in qualifying compared to the races.
Active control valves between any part of the power unit and the air intake will also be banned.
Sump breather pipes currently feed excess oil back into the engine through the intake - rather than out of the back of the car as happened decades ago - and this will prevent clever systems diverting it back into the engine for a power boost.
Teams will also be limited to a single oil specification per engine at any given grand prix, which must be declared with a sample provided beforehand.
This will prevent the possibility of teams using a 'qualifying oil' to produce extra power, and switching to a more durable type for the race.