Christian Horner, who is the principal of the Red Bull team, has raised questions regarding the recent speed gains by Mercedes. He brought the concern regarding the straight-line speed’s “significant rise” with their power unit. Red Bulls said that they have not made any significant changes to the power unit other than fitting a new engine in Hamilton’s car. Mercedes racers Valterri Bottas and Lewis Hamilton have won the last two Grand Prix with Bottas winning by a margin of more than 14 seconds against Max Verstappen.
You can see across all their teams Mercedes obviously have some reliability issues they are managing, which is unusual for Mercedes. But their performance is still incredibly impressive. Whether one comes at the expense of the other, I don't know, but if you look at some of the speed deltas on the back straight at some points it was 15-20km/h, which is more than if there had been DRS.
Our power units have been the most reliable since the introduction of the hybrid engines in 2014 and because the boundaries are being pushed we have seen examples of, let's say, unusual noises within the combustion engine that aren't completely understood at that stage yet. They caused some troubles in the past; we had some engines that basically failed and now it's about containing the problem because changing parts is not something you would tackle.
Toto Wolff, Mercedes boss