After just one day of testing in Barcelona, Williams have resolved the issues that troubled them during the Spanish Grand Prix, according to Felipe Massa.
While Valterri Bottas finished in a credible fifth place during the race, Massa struggled badly with tyre degradation having been quick during the pre-race practice sessions earlier.
Speaking to crash.net after Tuesday's first day of testing at the same track, Massa revealed that they have found the cause of the problem.
"Honestly I also did a run and had none of the problems in terms of degradation compared to what I had in the race," Massa said.
"The only difference in the race is that I was in traffic, so that was the only thing that I had in the race that I didn't have [on Tuesday]. So it's something that we need to really be ready for, especially in races where you are going to be behind people and trying to understand what to do."
While Williams had a productive day on in Spain on Tuesday, Massa confirmed that they didn't test any of the new parts having given up on developing the rear wing further.
"We did more or less everything we were supposed to do. We didn't have much mileage so we did some laps in the wet which was also positive to look at some issues that we had in other races in the wet which we've got better at, but we had some things to try and I think it was positive to do some laps in the wet," he added.
"I did some set-up work looking at how the weekend was and I think it was good to do. I also did some aerodynamic working; not some new parts but some aerodynamic work that we had to do."