Pirelli's pre-season tyre test programme has entered its latest phase with the Italian company's wet and intermediate rubber taking to the track for the first time, at the Valencia circuit in Spain.

The test also marked the first time that Pedro de la Rosa has driven for Pirelli, having been announced as test driver last month.

Following on from work carried out to define both the compound and structure of Pirelli's slick tyres, which will be offered to F1 teams in four different variants next year, the focus has now switched to tyres for wet conditions.

Valencia was chosen because of its technical and compact nature that allowed Pirelli's engineers to assess every aspect of the tyre's performance.

In order to make the track wet, it was sprayed with water during both days of the test: a light covering to check the performance of the new intermediate tyres and then a more dense covering to try out the full wet rubber. Although conditions remained warm and dry in Valencia, with ambient temperatures in the region of 24 degrees C, it is easier to test wet tyres when it is not actually raining as the water on the track dries more consistently. This enables accurate data to be recorded: an essential priority when testing.

Driving last year's Toyota TF109, de la Rosa covered just over 650 kilometres during the course of the two days, having started his programme running on slick tyres in order to establish a benchmark time.

The 39-year-old Spaniard was recruited because of his recent Formula One experience and renowned testing abilities, which allowed him to give plenty of useful feedback to Pirelli's engineers.

"As we were running our intermediate and wet tyres for the very first time, effectively our programme was starting from scratch once more," said Pirelli's motorsport director Paul Hembery. "We worked through our schedule exactly as planned, and we were able to get an initial impression of our performance in wet and drying conditions. This has enabled us to identify the areas in which we are strong and the areas that we need to develop further, which is always the aim in testing.

"It's been great working with Pedro de la Rosa, whose experience has given us a well-informed perspective on the characteristics of our tyres. So far our schedule is going exactly to plan, and we look forward to continuing our work at what is a very exciting time for us during the next test sessions as well as back at base in Milan."

"It's a real pleasure for me to be working with Pirelli this year," said de la Rosa, "and I'm delighted to have finally had the chance to try out these tyres. We completed all the work we wanted to do during this initial session, and now we have a clearer idea about future avenues for development."

Pirelli also used the Valencia test to carry out development of its new GP2 rubber, with Giorgio Pantano driving the new Renault-powered single-seater.

The Italian manufacturer's next test will be at the Circuit de Catalunya in Barcelona at the end of the month.