Ferrari believe that the change in Pirelli tyres for 2019 is one of the reasons that have hindered the performance of their car. Pirelli reduced the tyre thickness of all its compounds by 0.4 mm this year to protect tyres from blistering. An additional consequence, according to many teams, has been how much harder it has become to get the tyres up to temperature.
Ferrari team principal Mattia Binotto said during the Monaco Grand Prix weekend:
"The main difference is that last year we had very good warm up with the tyres and we were all focused and concentrating on cooling the tyres as much as we could, to keep them working because the lower the temperature was the better the grip was."
"The tyres of this season are quite different in this respect. Warm-up is a lot more difficult and to achieve what we may call the window, the temperature target of when you have the best grip from the tyres itself, you need to heat the tyres."
This does in effect explain why Ferrari has been able to do better on tracks where the softer compound is available or a more abrasive surface is in play, like in Baku and Bahrain. But then, on the other hand, the same car was quicker than Mercedes during the Pre-Season testing, but suffered heavily during the Spanish Grand Prix at the same test.
Bingo, on his part, is not ruling out the possibility of something fundamentally wrong with the car that could be playing a role in the performance deficit as well. Binotto further said:
"You can achieve [heat in the tyres] through braking temperatures and cooling the rims, but also it is downforce no doubt,"
"The downforce has an absolute value, but it is also how you may balance the downforce at high speed to low speed."
"It may be as well how you may even target your aero development efficiency versus maximum downforce itself."
"I think we have a quite efficient car, as you can see on the straights, but it doesn't mean we have the car that has the highest downforce in the pitlane."
"It is right to question ourselves if we should look for different overall targets of how to achieve the final performance."
With varied factors getting accounted for, it's becoming more and more clear that the reason behind Mercedes stealing the march on the rest of the field is a accumulation of different factors. All of them have combined to give the Silver Arrows the margin they are enjoying.