As F1’s oil burning saga rumbles on, the FIA have closed yet another loophole after Mercedes requested clarification regarding the oil used in the “pressure charging [turbocharger] system”.

With rivals accusing one another of burning oil to increase performance, the FIA have taken steps over the past months to close various loopholes while limiting oil burning.

The latest relates to the turbocharger.

According to Autosport, Mercedes’ head of product engineering capability at Brixworth Chris Jilbert recently wrote to F1 race director Charlie Whiting seeking clarification.

In the letter he asked: “With the exception of transformer oils used within ERS cooling circuits, and hydraulic oils used for PU actuators (both of which should have zero consumption in operation), do all oils (and specifically, any oil used in the pressure charging [turbocharger] system) used in the power unit need to comply with article 20?”