The collision between Sebastian Vettel and Lewis Hamilton in Baku has not been the only flashpoint between Ferrari and Mercedes this year. Ahead of the Azerbaijan Grand Prix weekend, the FIA sent out a note to all teams reminding them that burning engine oil as fuel was not allowed, following suspicions that some have been using a scheme to generate a power boost in qualifying trim.

OIL BURN TACTICS FUEL CONTROVERSY

While the Vettel/Hamilton clash grabbed all the headlines post-Baku, it should not totally overshadow the fact that their respective teams were already at loggerheads over the use of engine oil as fuel in a bid to improve qualifying performance.

Interestingly, the topic was first raised by Red Bull, as the Milton Keynes-based outfit has been questioning Mercedes’ stunning one-lap pace in recent years. Having asked for clarification as early as 2015, Red Bull sought further answers from the FIA over the winter, with Formula 1’s ruling body confirming that using oil in such a way was indeed illegal.

The story took another turn in between the Canadian and Azerbaijan Grands Prix when the FIA released a new technical directive on the matter.

“We wish to remind you that, as previously stated in various meetings and re-emphasised in TD/004-17, we consider the use of oil as fuel to be prohibited by the Technical Regulations,” wrote Marcin Budkowski, the head of the F1 technical department at the FIA.

“For the avoidance of doubt, the only fuel that may be used for combustion is petrol, and the only permitted characteristics of that petrol are clearly set out in Article 19 of the Technical Regulations.

“Even though the Technical Regulations do not directly specify the permitted characteristics of engine oil used in F1, we would consider any attempt to use additional components or substances in oil for the purpose of enhancing combustion as a breach of the Technical Regulations."

Why did the FIA feel compelled to issue the reminder?

This time, it was Mercedes that requested a new clarification. The reigning world champions are suspecting their rivals from Maranello of using their auxiliary oil tank to spray oil into the V6.

Last winter, Ferrari would have apparently asked FIA Race Director and Safety Delegate Charlie Whiting whether the regulations allowed the use of two different specifications of oil and whether the oil’s chemical makeup was defined. This would have triggered Mercedes’ suspicion that the Scuderia was using the auxiliary tank to stock a specific oil, which would be burnt as fuel in qualifying.