Pirelli is considering plans to widen the rear Formula 1 tyres for next year in a bid to ensure they can cope with the demands of the new 2014 engines.
F1's tyre supplier is pushing to finalise the specification of next year's rubber, which will have to deal with the increased torque of the 1.6-litre V6 turbo power units.
An early season request for teams to supply data on the performance figures of the 2014 cars only drew a response from five teams - which has left Pirelli concerned about the exact targets it needs to aim for.
With Mercedes believed to be worried about how tough the new engines will be on tyres, Pirelli has been asked to consider making rear tyres wider and larger in diameter.
This idea has been floated with the teams, but many of the leading outfits are not keen on the move as it would lead to an expensive redesign of suspension concepts.
With the teams at loggerheads over what should be done, AUTOSPORT has learned that the FIA has now stepped in and demanded that each outfit supplies the 2014 performance information to Pirelli in the next few days.
Only once it has the data available can Pirelli then decide on what needs to be done for next year.
PIRELLI EXPECTS TO BE CAUTIOUS
In a bid to help it make an informed decision, it is understood that Pirelli has been given an extra month to finalise the specification of the 2014 tyres.
That deadline had originally been at the start of September, but it has now been moved back to October 1.
Speaking earlier this week, Pirelli motorsport director Paul Hembery said that his company would likely be more conservative with its choices for next year.
"We have already said that it is probably a year for us to be quite cautious as they [the teams] have a lot of challenges," he said.
"It is a year for them to be talking and explaining where they are. There will be a lot of talk about the engine manufacturers next season."