FIA tells Pirelli to make formal request for move to Bahrain

The request was made by Charlie Whiting at a heated meeting at Suzuka on Saturday at which Niki Lauda put the case for Bahrain and Christian Horner argued for remaining in Barcelona.

Pirelli's Paul Hembery and Toto Wolff were also in attendance.

Pirelli has made it clear that having developed its new wider tyres on the modified mule cars it has to run them in hot conditions on the definitive 2017 models, which will feature substantially higher downforce levels.

Aside from hotter weather there are also specific reasons why Pirelli would prefer to run at Bahrain rather than Barcelona.

"You know it's not a mystery that we prefer to go to Bahrain," said Pirelli technical boss Mario Isola.

"For us it's much better, because we can have more representative situation, and we can better understand the behaviour of the compounds. But there is still open discussion between Barcelona and Bahrain.

"I understand the position of the teams, they want to test the car, they need to test the car, and they want to discover if the car is working as expected. So Barcelona could be also possible for them.

"For us it's a bit more difficult because from what we have to see, the integrity, the carcass, the construction, we assess with indoor tests, not on track."

Isola says factory testing does not tell the full story: "We tune our indoor tests on the simulation that we receive – we receive from the teams the expected performance at the beginning of 2017, and the end of 2017, so we have also an idea of the evolution.

"And of course when we have the level of integrity required, we take the end of 2017, having a margin. We do this work with indoor tests, and this is done.

"But compound wise, it is difficult to do it with indoor tests. We can have some ideas, some indications, but it is the track at the end that is giving you the real behaviour of the compound."

Isola says Bahrain is a good venue at which to try the full range of compounds, with the exception of the hard.

"In Bahrain for sure we can test the medium, the soft, the supersoft, that is the centre of the range, and it is also possible to understand the behaviour of the ultrasoft.

"We can have a good idea of four compounds – that is not bad. The hard in Bahrain is a bit too hard. Of course you can use the hard and you can understand the performance of the hard, but it's not the ideal circuit for the hard compound.

"In Bahrain, you need a lot of traction. For example, one of the main effects we are working on is to reduce the overheating, and the overheating is mainly coming from the rear due to traction.

"In Bahrain this is something that you can this very well. It is similar to sector three in Barcelona, where you need traction, and where the drivers start to complain about the overheating and lack of grip from the rear."

Although Pirelli has a lot of experience of testing at a cool Barcelona and then heading to races in hotter climates, Isola says that the Spanish track can make it hard to identify problems.

"There is pattern, but if you have a major issue like heavy graining for example this kind of effect can hide the result, and it's difficult to find this pattern.

"In a normal Barcelona condition of course you test your tyres, you understand a lot of numbers, and then you can let's say expect this number and try to understand what happens in many other tracks.

"But if you have graining, because Barcelona for example is a circuit where the front left is heavily loaded, and if it is cold you have graining, and in that case you start to have understeer, and then it's difficult to understand the real performance of the car."