A report in German media suggests that a private technical directive was issued to Honda during the past month, resulting in their power unit falling behind Mercedes once again in the battle for supremacy.
The roll out of Honda's second power unit of the season at the French Grand Prix saw a clear step forward for the Japanese manufacturer, with that engine gaining performance as a result of reliability fixes that allowed Honda to utilise more of their engine's potential. It's important to point out these gains came about as a result of fixes on the reliability front, rather than being related to performance development.
Red Bull enjoyed a clear straightline speed advantage over Mercedes at Paul Ricard and the two races in Austria. This was aided by Red Bull's lower downforce package, with Red Bull gaining a few tenths of a second per lap over Mercedes down the straights.
But, at Silverstone and Hungary, this advantage seemed to disappear, with Mercedes romping to the quickest times in qualifying at both venues. According to Germany's Auto Motor und Sport, this could be down to a technical directive issued in private to Honda.
According to AMuS, Mercedes sources say Honda have been slowed by a directive that has targeted how the Honda power unit utilises its energy management - an area Honda have outlined themselves as an area of major improvement.
As technical directives are not released to the public, there's no confirmation from the FIA as to whether such a directive has been issued. RacingNews365 has reached out to Honda for comment on the situation.
Are Mercedes cooling their engine before going on track?
According to AMuS, there's also a theory that Mercedes could be using a form of engine cooling in order to generate a little more horsepower as the car hits the track. According to Red Bull and Ferrari sources, Mercedes could be cooling the plenum of the engine.
This theory has come about as its effects only last for a short while as the engine warms, which would work effectively for a qualifying run or at the start of the race. This could be borne out by Mercedes' improved qualifying performances, and the seemingly large advantage in power that Hamilton appeared to have on the run from Luffield to Copse at Silverstone on the opening lap.