Formula 1 teams are facing delays in pushing on with their 2017 car designs because the lack of a contract between the FIA and Pirelli for next year means much-needed wind tunnel tyres have not been released.
With F1 switching to wider tyres next year as part of a move to make cars up to five seconds per lap faster, teams are well aware that the aerodynamic influence of the new rubber will have a major effect on their car concepts.
But although Pirelli has already manufactured the first batch of wind tunnel tyres that teams will want to use for development, it is understood that they are unlikely to be given out until the Italian company's final contract with the FIA for its 2017-2019 F1 supply deal has been signed off.
Pirelli motorsport director Paul Hembery confirmed in Australia that the wind tunnel tyres were ready, but suggested that until there was clarity over 2017 contracts, it could not distribute them.
"We physically have them available," he said. "We are just finalising details of contracts with the FIA and then we need to do the teams. Also we need the final regulations to be confirmed."
Without the wind tunnel tyres – which are essential for simulating how the actual rubber will deform under load – then teams are limited to just CFD simulations for their 2017 car concepts.
The computer data – which will be based on an anticipated 405/670/13 rear and 305/670/13 front – will be of limited use however and teams will not want to invest too much effort in case the wind tunnel rubber performs differently.
Although Pirelli's success in winning the F1 supply contract from 2017 to 2019 was announced by Bernie Ecclestone at last year's Russian Grand Prix, its contract with the FIA has not yet been ratified.
The exact reasons for the delay are unclear but it is known that there remain key demands from Pirelli about securing a proper testing programme ahead of 2017.
The idea of using a V8-powered car to kick off its development work over the next few months has been agreed in principle, but there has not yet been an official sign off which chassis it will get nor which teams will be running it.
Furthermore, although F1's 2017 technical regulations have been agreed, there remains scope for changes to be made until the end of April, something that Pirelli is mindful of.
The delay in releasing the wind tunnel tyres will put the FIA contractual situation, and the testing matter, in to sharp focus and may well force teams to do more to help resolve remaining uncertainties so they too can get on with their work.
Hembery remains hopeful that a testing solution will be found – both for getting hold of a car and having enough days to run a proper programme.
"We are getting close to getting a car," he said. "We've also had very clear assurances that we will get 12 days, hopefully with two cars but a maximum of three.
"Ideally we would like to get some work done on a previous generation V8, so we can do some of the conceptual work.
"We are changing concepts in terms of compounding and structures, which you can do initially screening on a V8 before you move to a hybrid version of the 2017 car."