Formula 1 drivers are still not convinced the sport is ready to ban tyre blankets amid safety concerns.
The blankets have been used for four decades to pre-heat tyres before the go out on track. But there are now limits to what temperature they can reach and how long they can be used for.
And F1 chiefs want to get rid of them altogether. Their argument is that, as the blankets require a notable amount of energy, their use goes against F1's attempts to become more sustainable.
Supplier Pirelli has been developing compounds to be used on track which do not require the use of the blankets. Whether or not they will be used next year depends on the outcome of a vote to be held at the end of July.
Several test events have been held in recent months to gather date on how effecting those new compounds are. The most recent took place this month, in the days after the Spanish Grand Prix at the same Barcelona track.
Warm temperatures meant that the drivers who took part found grip easier to come by compared to previous tests. However, they remain unconvinced about the effectiveness of the compounds on colder tracks.
"In hindsight it probably wasn’t tested in the right conditions at the right circuit," said George Russell, who shared duties with Mick Schumacher in the Mercedes test. "If you go to a circuit such as Barcelona which is quite an aggressive Tarmac, it was 40-odd degree track temperature, fully rubbered-in from the race weekend.
"The tyres were very sketchy coming out pit lane but by about turn five on the out-lap it was at a respectable level. But if I compare that in contrast with the start of the year when I did one run in Jerez in 10-degree track temperature it was extremely difficult getting out of the pits.
"If I'm being totally honest, I don't think we as a sport are at a position yet to bring these tyres into a racing scenario. I would be very concerned for all the mechanics in the pit lane during a pit stop. I'd be very concerned for the out-lap from a race.
"In cold conditions there will be crashes, I have no doubt about it. And I think there's a lot of work and expensive development going into these tyres I feel like that could be put elsewhere."
Fernando Alonso agreed with Russell's statement that the results of the most recent test were helped by the Barcelona heat. And he too "doesn't see the reason why" F1 should get rid of the tyre blankets.
And Charles Leclerc came to a similar conclusion. The Ferrari driver said: "In the conditions that I had during the test, it was good, it went well. But in lower temperatures, I don't know... I haven't tested these tyres in lower temperatures and that's where the big question mark is.
"So it's very difficult to answer whether I will be happy to go. I would like to maybe test those tyres in different conditions and then see whether they are raceable in all conditions."
