Red Bull are concerned by the unexplained increase in Mercedes' straight-line speed since the British Grand Prix. To that effect, the team continues to question the FIA, according to Auto Motor und Sport's Michael Schmidt, who wrote:
"According to measurements of the World Championship runner-up, Mercedes has been mobilizing much more power since Silverstone, especially when accelerating. The Silver Arrows were faster on the straights in Turkey with the DRS closed than Red Bull with it open. (Red Bull) Team boss Christian Horner can only explain this power boost by the fact that the rival found power somewhere and somehow. One suspects that Brixworth is fishing in grey areas."
He went on to say that while an initial inquiry with the FIA received a negative response, Red Bull continues to keep the issue "simmering" and that "further suspicions are being investigated".
Mercedes stoic on their stance despite Red Bull's questioning
Mercedes, for their part, have maintained that they currently run the same specification of engines, with the only difference being their improved understanding of the package during the season.
The fact that Mercedes saw a sudden increase in power over the same British Grand Prix weekend that it brought its major upgrade does provide credence to its argument.
Touching on Mercedes, Schmidt stated:
"Mercedes claims that the engines have been identical since the beginning of the season. In the course of the season, they have only improved the driveability somewhat."
However, the improved speed of Mercedes-powered McLaren and Williams during this time too raises question marks, as Schmidt stated:
“Because Williams and McLaren have also suddenly improved since the Hungarian GP, the suspicion has been circulating that Mercedes is simply releasing more power for Saturday and Sunday in general and is therefore now paying for it with damage. An engineer denies: Nothing has changed in the calibration of the engines.”
The difference in straight-line speed was evident during the battle between Hamilton and Sergio Perez at the Turkish GP where the Mercedes had considerably better straight-line speed than the Red Bull despite running a higher downforce setup.
Whether all of these gains will be attributed to the major upgrade package brought at the British Grand Prix remains to be decided by the FIA. In the battle for supremacy, both teams are pushing the limits of what their machinery can do. Only time will tell how many of those gains were achieved through legitimate means.