The issue had died down, but the FIA warned again ahead of the Azerbaijan weekend that oil must not be added to the fuel under any circumstances.
“Why? Because Mercedes obviously asked the FIA for clarification,” said Germany’s Auto Motor und Sport.
“After checks in Canada, apparently one team returned doubtful results. The FIA did not want to confirm this, but Mercedes suspects the Ferrari has an additional oil tank,” the report added.
However, Ferrari engineering chief Jock Clear insists the Ferrari is simply a good all-round car.
“I think we can say that the standout characteristic is that there is no standout characteristic. It just seems to be a very well behaved car in all areas,” he said.