However, the technical analysis that appeared on F1's official website yesterday – focusing on the rear diffuser designs used by F1 teams on their 2009 challengers – shows that the two interpretations of the FIA rule book have led to “highly innovative” and “very interesting” designs, not at all illegal.
“Williams' interpretation of the revised diffuser regulations is highly innovative. Much of the diffuser's central section is actually lower than the outer sections. However, clever shaping of the rear crash structure immediately below the rear light effectively creates a second central section (red arrow). In combination, the result is a central section that exceeds the 175mm height allowance that applies to the diffuser alone,” shows the technical analysis published by the aforementioned source.
“Toyota's diffuser makes a very interesting interpretation of the revised 2009 rules. By exploiting regulations that allow extra bodywork within a 150mm zone in the centre of the car, the team appear to have cleverly shaped the TF109's rear crash structure so that it effectively lengthens and heightens the diffuser's central section, which also features a very low splitter at its base,” it says on the system used by Toyota.
The report points out, however, that Toyota's design has led to speculation concerning its legality, but avoided to give a verdict.
Swiss magazine Motorsport Aktuell also revealed – not officially confirmed, of course – that the two designs are legal and that FIA doesn't plan to intervene unless one of the other F1 teams will submit an official protest on the matter.