Auto Motor und Sport reports that Mercedes’ request followed Barcelona testing, when the team suffered from extreme blistering.
Pirelli boss Mario Isola confirmed: “The new asphalt is blacker and smoother and producing even more grip. This can lead to overheating.”
Mercedes told Pirelli that a solution might be to reduce the thickness of the rubber layer on critical circuits like Barcelona.
“We would have done it anyway,” Isola insisted.
So in Barcelona, Silverstone and Paul Ricard later this season – circuits that were all recently resurfaced – the rubber layer of the tyres will be 0.4mm thinner, reducing the weight of the cars by a kilo.
Normally, Pirelli would need 70 per cent agreement for an in-season tyre design change, but in this case the Italian tyre maker is using the emergency safety argument.
Rival teams are not happy.
“We have no problems with blisters,” a McLaren source said.
Red Bull’s Daniel Ricciardo agrees: “Our car is gentler on the tyres than the Mercedes.”
An unnamed team boss added: “Why should we change the tyres if Mercedes has a problem?”