Today was another day governed by inclement weather on the Algarve, which grew so severe at times that running was considered to be dangerous. Indeed, there were times when the teams must have thought they were running in Britain rather than Portugal, such were the unseasonal weather conditions, with hailstones blasting the track at one stage during the course of the day.

Once again, Sebastien Buemi was the pace-setter, though his times this week are fairly meaningless as he is continuing with a 2008 car. The Swiss driver evaluated three different types of tyre over the course of the day: dry (for one cautious run,) extreme wets and intermediates. Other than that, his programme was all about fine tuning the electronics systems and gearbox settings.

Due to the adverse weather conditions, McLaren continued using its 2008-spec rear wing as a precautionary measure to increase downforce. Nonetheless, Pedro de la Rosa (above) was able to dodge the hailstorms to complete three long runs - including one 22-lap stint - to provide the team with further information on the MP4-24's handling characteristics and components. Opting not to run with KERS, the team reported that the car performed without any mechanical or electronic problems.

World Champion Lewis Hamilton joins the team tomorrow for his first run in MP4-24, indeed, his first official team driving duties since last November's Brazilian Grand Prix.

Jarno Trulli took over from Kamui Kobayashi for Toyota, but the heavy rain just before the session started restricted his early running and the situation did not improve much during the day. The Italian had planned to gather initial set-up data about the new car but the weather severely restricted his running. However, at least he used the opportunity to gain some data on the TF109's behaviour in the wet and finished the day with 30 laps under his belt. Timo Glock takes over the wheel of the TF109 tomorrow.

"It is very hard to give my first impressions of the new car because the track conditions today were not very good at all," said Trulli. "It was very wet and there was no grip. It is a pity that I could not do more laps but there was little to gain considering the conditions. Hopefully the weather improves for Timo later in the week and we can get a better idea of the characteristics of the new car."

"Today was all about the weather," added, Pascal Vasselon, "and we had to fit our running around the showers, which meant we didn't get as much time on track as we would expect. On the positive side, at least we have had quite a bit of experience now with the TF109 in wet conditions and this could be helpful if there is no rain over the rest of pre-season testing. The car ran without any trouble today and we are constantly learning more about it, which is an interesting experience, and I am happy with the progress we have made so far. I hope tomorrow the weather is kinder to us and we can complete more laps."

Nelson Piquet remained in the cockpit of the R29, but endured a frustrating day, completing a handful of laps as the team continued to check the
systems on the car. With better conditions forecast for tomorrow the French team looks forward to running the new car on a dry track when Fernando Alonso gets behind the wheel of the R29 for the first time.

It was another wet and windy day," said a clearly frustrated Piquet, "and so we were not able to do many laps. It's frustrating to lose so much track time, but this is something that can happen in winter testing. I've yet to drive the new car on a dry track and so it's difficult for me to really say how different it is to the R28, but the forecast looks better for tomorrow and hopefully we can learn more about the car then."

"It has been quite a frustrating day," added Christian Silk, "and the weather has made things very difficult. As it's a new car we don't want to risk it by doing lots of wet weather running and so we've done limited mileage today. The rain also makes it difficult to learn very much about the car, but all the teams here have the same problem and so in that sense we are all in the same position. We are hoping for a better forecast tomorrow so we can get on and do some proper running."

Nico Rosberg took over from Nico Hulkenberg for Williams, the German completing 31 laps.