Pirelli is facing resistance from Force India as it tries to get unanimous approval from Formula 1 teams for its tire modifications.
Following a dramatic week of behind-the-scenes negotiations with teams and the FIA about what it can change on its tires, Pirelli is hoping to tweak the rears for the next race in Canada to eradicate the delamination issues that have blighted recent grands prix.
But while the FIA is happy that there are safety grounds for Pirelli to make the alterations it wants to – which will essentially be replacing the steel belt in the rear tire with the Kevlar used last year – not all teams are eager for such a tweak. It is understood that Lotus, Ferrari and Force India have expressed reservations about such a move, and the latter team is especially unhappy about the situation.
Force India is well aware that even minor tweaks could have an impact on the competitive form it has shown so far this year. It is specifically questioning whether there are actually enough safety grounds for there to be a need for changes at all, especially as none of the rear failures have resulted in the tire deflating.
Sources with good knowledge of the situation claim that one of the arguments being put forward is that Pirelli motorsport director Paul Hembery admitted in a recent press release that safety was not being compromised by the tires.
"It's important to point out that these delaminations, which occur when the tread comes off, do not compromise the safety of the tires," he was quoted as saying.
Hembery was seen in discussions with Force India's deputy team principal Bob Fernley in the team's motorhome on Thursday to try and make progress on the matter. Although Force India would be unlikely to have a veto on even minor changes being made to the tires – because the FIA is satisfied that there are safety grounds – Pirelli is eager to get support from all teams on the matter.
"We are trying to seek a solution that is supported by everyone, and is fair to all the teams," Hembery said.
A change of the belt material at the rear would likely result in the rear operating temperatures of the tire being reduced by up to 50 degrees. That move could help teams like Mercedes which has struggled with overheating rear tires so far this season. It would not be enough, however, to benefit a team like Red Bull that has found its performance limited by the front tires this season.
Pirelli currently only has plans to tweak the rear tires, because of the delamination issue, and will stick with the current fronts unless there is unanimous support from the teams for an alteration to be made in the longer term.