Jaime AlguersuariThe durability of Pirelli's intermediate tire impressed drivers during the first hours of today's Barcelona test.

The track was damp at the beginning of the day, allowing teams to run both the wet and intermediate tire before it dried out. While the dry compound tires have degraded faster than most drivers expected, they found the intermediate stayed consistent as the surface dried.

"It was important to drive on intermediates today, to be honest, I was quite surprised by them," said Toro Rosso's Jaime Alguersuari. "The track was not completely wet, quite humid, and it was drying up. We were quite fast, able to run in the 1m40sec and quite consistently. The tire did not degrade at all."

Sauber Kamui Kobayashi agreed it compares well to Bridgestone's intermediate, but says the tire's performance is not as good.

"It has a lot poorer grip but the consistency was better with Pirelli – that seems to be OK," he said. "It's very difficult to judge where we have to be on the wet tires or intermediate tires. I think the compound itself is very hard."

Alguersuari tried to find a crossover point between the intermediate and slick tires, but said he went a bit too early for the tire.

"We tried the slicks in the wet and humid conditions and it wasn't really working," he said. "We needed to go back to the garage and wait a bit more time to go back and perform the same lap time on the slicks.