Romain Grosjean says the “ridiculous” tyre pressure limits were in part responsible for Haas F1's struggles on Friday in practice for the Chinese Grand Prix.
After a storming start to the team's debut season, Grosjean found himself well off the pace, ending the first day of running at the Shanghai International Circuit down in 16th position, almost 3 seconds off the pace – and 1.1 seconds off Valtteri Bottas in P10.
“It's been very tricky driving the car given the fact we don't have any information from previous years here,” Grosjean said. “The Pirelli tyre pressure limit has been ridiculous today [too], and everything is up to the roof and the cars are undriveable. There is a lot of work we need to do, a lot of questions we need to ask ourselves.
“There is no reason why we lost three seconds from Bahrain, so it's back to the basics, understanding what's going on, and I'm sure some explanation is going to come.”
Asked to explain what is wrong with the tyres pressures, he replied: “Out of the garage the front-tyre pressures are 23psi, which is absolutely ridiculous, with the rear 21 and a half.
“We have had on the rear some high limit, but with that high on the front you just don't get any feeling. It's like a piece of wood, and not driveable. Back in time we were four to five psi lower than that.”
“Recently we've already had some drastic limits, around 21, 20, that still gives you a bit of a feeling and is still very high,” he continued. “Back in Michelin terms it was 15, 13 in Monaco, and there in 2012 people were running 16 and 18. So imagine on track we are 26 at the front, hot, and 23 at the rear.
"It's almost a roadcar.”
Meanwhile, Pirelli boss Paul Hembery admits traction was at a premium and says they will look at it after discussions with the teams and drivers.
“Traction was certainly at a premium, it's true to say. The process is that on a Friday we take the data, the telemetry from the teams and we compare that to the pre-race simulations, and then we verify if the prescriptions we have are correct,” he explained.