Bridgestones soft tyre proved to be the fastest rubber on track at the Circuit de Catalunya near Barcelona for the first day of the Spanish Grand Prix. In warm and sunny conditions, Nico Rosbergs AT&T Williams set the fastest lap time in the afternoon practice session, a 1min 21.588secs. Track conditions improved throughout the day and 38 degrees Celsius was the hottest track temperature recorded. Brawn GP driver Jenson Button was the fastest driver in the morning session, using the soft compound to set a time of 1min 21.799secs. This was the first time that the current hard compound has been used in Barcelona, although this compound was previously used at the Malaysian Grand Prix. Q&A with Hirohide Hamashima – Bridgestone Director of Motorsport Tyre Development What was significant about todays running? Today we saw the track improve a lot during the course of the day as the surface improved with rubber put down. In the morning it was interesting as Jenson Button set the fastest time using the soft compound, but Jarno Trulli was second fastest using the hard compound. The soft compound was on average 0.6 seconds faster than the hard here. How do you expect this allocation to work over the weekend? After one days running here we predict that the soft tyre could be the preferred tyre for qualifying as well as the race. Both tyres have performed well today. This is a different hard compound from the one we tested here in the pre-season, but teams have quickly learnt its characteristics. The hard tyre does take longer to warm-up than the soft, and its best lap time is slower. Some teams found the hard compound we used in the winter tests here difficult to warm up, however everyone was able to get reasonable grip today which means our compound changes have worked. The soft compound has not shown any particular issues with degradation so we would expect that to be the preferred tyre for the race.