Fernando Alonso topped the timesheets of the penultimate day of the first Barcelona test however, it was the times posted during the afternoon, as attention switched to race distances, that really mattered.

With much talk of heavy rain tomorrow, attention this afternoon switched to race simulations, and whilst tyre degradation continues to be a major talking point, especially the soft compound, so too is the pace of some of the cars during the long runs.

After yesterday's exhaust issue - explained away earlier by Luca Marmorini, today's programme at Ferrari was completed without any problems. The programme, which included set-up work aimed at adapting to the soft tyres, which Alonso was trying for the first time, and the hards.

"Today we concentrated on a comparison of the compounds, starting with the Soft and moving on to the Hard in the afternoon," said the Spaniard. "The track was colder than yesterday, especially in the morning, which made it harder to adapt the car and find the right grip level. We tried various aerodynamic configurations and for the first time, we made some set-up changes to get a good understanding of tyre behaviour and degradation. With every change we made, the car reacted as I expected and it was useful to try out the different settings, especially to understand which direction we need to go in next week, when there will be a greater emphasis on performance.

"Once again this year, the tyres will be one of the crucial aspects to manage," he admitted, "they are softer and quicker, but also less consistent and they degrade rapidly with every lap. We will have a lot of work to do to understand how best to balance the car, but that applies to all the teams."

After three days in the F138, Alonso hands over to teammate Felipe Massa for the final day of this first Barcelona test.

Nico Hulkenberg, was another driver to notice the high degradation on the softs, which he too was trying for the first time. Having started the day testing aerodynamic components in the afternoon he mainly concentrated on long-runs with high fuel loads.

"It was a positive day," said the German. "We got a lot of testing done with just minor problems. I ran the soft tyres in the morning for the first time to get a feeling for those, which was interesting. The car is performing pretty well, and I'm as happy as I can be."

"Overall it was a very productive day," added Head of Track Engineering, Tom McCullough, "which is particularly important as the forecast suggests rain is likely tomorrow. As in previous days, we have used the initial running for data gathering of new aerodynamic parts while the temperatures were low.

"For the first time at this test we used the soft Pirelli tyre, which performs well for the first timed lap," he added. "The high tyre degradation makes testing difficult, but that is the same for everyone and we have to adapt to it. Nico and the engineers continued to make good progress with the car set-up and he will now hand the car back to Esteban for the final day of the test."