SPA-FRANCORCHAMPS, Belgium -- Felipe Massa has branded Pirelli's tyre pressures for the Belgian Grand Prix "a joke" after the opening day of practice.
With tyre pressures set at 23.5PSI front, 22 PSI rear, many drivers appeared to struggle during the first three hours of track time in Belgium. After finishing 17th in FP2 Massa said the chosen pressures are too high.
"Definitely you enjoy [Spa] even more if the behaviour of the car is better but today the behaviour of the car was pretty difficult so we were struggling a lot on the short runs and the long runs with the tyres," Massa said . "It was a very difficult Friday, definitely we are going to have a very long evening to try and fix the problem.
"I guess one of the issues is the tyre pressures. I've never run such high tyre pressures like we have, to be honest in my whole career. This is a bit of a joke to be honest."
Toro Rosso's Carlos Sainz also weighed in on the issue, saying the tyre pressures and the blistering on Pirelli's compounds are unacceptable.
"I think the tyre pressures only accelerate the problem you have in the car, Sainz said. "I'm convinced there is something to improve, something to understand, and the tyre pressures are exaggerating this problems. It's clear that these blisterings everyone is having ... I wouldn't be happy to see them in the race because they are too big.
"In all four tyres, even if you don't flat spot or nothing, you just find massive chunks of tyres coming up, and we've gone from one extreme with these tyre pressures. The super-softs after two laps are undriveable, Eau Rouge becomes like driving on an extreme wet on a dry track, very slippery. Not very comfortable, I would say."
Pirelli's response
Pirelli will make a decision on whether to amend tyre pressures on Friday night after analysing the data from Friday practice and its own telemetry. However, the tyre manufacturer's Racing Manager, Mario Isola, says the teams had plenty of warning about how high the pressures would be in Spa.
"The procedure is the usual one, so we are receiving now the telemetary from the team's and we compare with the simulation," Isola said. "I have to say, it's not a surprise for these teams to have these kinds of pressures here, because at the beginning of the year we decided to take some representative high-energy circuits - one of which was Spa - so they knew in February that the plan for Spa was to have around 23-24 PSI front, and 22 rear.
"It was 24PSI [ahead of the weekend] and with the updated simulation we went down to 23.5, it's not a big difference but it's not higher than expected. Now we check with the usual system, the telemetry data. If we have room to do down, we go down.
"Maybe we have to increase if the severity of the telemetry is higher than the simulation... They have three hours to upload the data and we have three hours to analyse the data. So at 9.30 we are going to confirm or change prescriptions."
On the topic of tyres blistering, Isola said the hot temperatures at the traditionally erratic Spa-Francorchamps played a part.
"I would say considering the temperature of tarmac today -- 44 degrees -- to have blisters on the super-soft is not a surprise," he said. "In the past we came here with the medium-soft, it's a hard circuit, hard because the roughness is high, the energy that is going into the tyre is very high and that means the super-soft is a quite an aggressive choice. In qualifying we were expecting that would last for eight-nine laps, with these conditions probably less."