Formula 1’s rule makers have moved to close a loophole that could have seen teams burn oil to improve the performance of their cars in qualifying.

The sport has this season attempted to clamp down on the practice of using oil to improve engine performance by restricting the amount of oil which cars can consume.

However, a loophole in the amended regulations failed to cover off the practice during qualifying, where teams were able to top up, or transfer oil from, an auxiliary oil tank.

In theory, this process allows teams to conceal the amount of oil they’ve burned during the session and circumvent the regulations.

In response, the FIA’s head of single seater technical matters, Nikolas Tombazis, has issued a technical directive to teams.

“Following numerous discussions on the subject, we wish to clarify that in order to allow the FIA to monitor oil consumption during the qualifying practice session in a precise and timely manner, no oil may be added to the car nor may any auxiliary oil tank (AOT) be activated, i.e. there may be no oil transfer between an AOT and any part of the engine lubrication system,” read the directive.

Tombazis went on to state that exceptions may be granted when a request is received from the team, though only in specific circumstances.

It is unclear if the move comes in response to any suspicions the FIA may have over one, or more, teams exploiting the regulations, or whether it’s simply covering off the practice.