Rubens Barrichello set the fastest lap on the final day of Formula One pre-season testing at the Jerez de la Fontera circuit. The Brazilian's time of 1m19.832s, was set early in the day on the last of a series of eight lap runs on that proved to be a productive day for Williams after a largely problematic first couple of days.
Despite a slight drop off in performance immediately after his quickest lap to the tune of around 1.3s, the Brazilian was consistent thereafter and managed to amass a total of 103 laps. Not everything went smoothly for Barrichello after he caused one of several red flags towards the end of the day after stopping on the back straight with a hydraulic leak.
"We completed some long runs today and looked at trying some different things on the car," Barrichello said. "This morning was also the first time we could run a few new sets of tyres and get some momentum. The car performed, as it should do so I am happy with that. The day went with minor problems, but we have some good direction and it is great to get some more mileage on the car."
Completing 83 laps in the Sauber, Kamui Kobayashi ended the day second fastest with a1m20.601s lap. His time was however, somewhat of a solitary nirvana as his morning running saw the Japanese driver fail to dip below the 1m22s bracket. He was also another red flag culprit after spinning into the gravel before lunch, then encountered some powertrain issues yet he still completed some consistent lap times with a heavier fuel load.
"For me these two days have been very interesting," declared Kobayashi. "Although we lost track time today, we still covered some good mileage and I have learnt a lot more about the character of the new tyres. We still have to work hard but to me it was a positive test."
Before switching to a programme focusing mainly on long runs, crowd favourite Fernando Alonso set the third quickest lap with a 1m21.074s and once more completed the most laps with 115. The Spaniard concentrated on consistent lap times between 16 and 20 lap runs - experiencing a drop off of roughly two seconds between the first and final laps.
"I'm very happy," commented Alonso. "After four days here at Jerez, no problems for Felipe [Massa], no problems for me, so we are doing some very good progress. We know that this year the tyre consistency is not the same as last year. One of the biggest changes for 2011 is how the tyres degrade, so we are working on that area.
"It's true that we found every day some new solutions we need to analyse. But to see performance of the car and to evaluate how competitive we are, we need to do it Sunday after the first race in Bahrain. Then we will say the car is good or the car is not so good," he added.
Toro Rosso had Sebastien Buemi driving on the final day, setting fourth fastest lap on a 1m21.213s and completing a total of 90 laps.
Next up, Bruno Senna for Lotus Renault GP focused largely on an acclimatisation and development programme for the team in what was his first day in the R31. Following Nick Heidfeld's pace setting performance yesterday, the German is all but assured of the seat vacated by Robert Kubica after his crash during a rally in Italy last week.
"It was an awesome day - my first chance to drive the R31 and I'm pleased with how things went," a delighted Senna announced. "It was very much a learning day for me. I had never used the adjustable wing or the KERS before, so I had to adapt to these. It's not easy at first, because there is a big workload and you are operating two factors that change the balance of the car, but by the end of the day it became more like second nature."
Team Lotus were represented by Heikki Kovalainen who set another quick time. Experiencing more reliability issues albeit a small water leak, the Finn spent the day on short runs within the 1m21a and 1m22s range yet managed to better the time he set yesterday by just over a tenth of a second.
"The combination of a number of small issues throughout the day and different weather conditions than the last three days meant we had a bit of a disrupted day," said the Finn. "We did manage to take another step forward with the setup options and that lap at the end proves there is good pace in the car."
On Friday, Michael Schumacher topped the time sheets for Mercedes GP yet on the final day, Nico Rosberg was unable to shrug off the reliability issues the team are currently experiencing and could only manage seventh with a 1m22.103s lap. The German was stuck in the garage with a lengthy precautionary engine change after he had stopped on the circuit earlier in the day.
"Today was a bit difficult," Rosberg explained. "Especially because of the precautionary engine change to make sure we could complete the running in the afternoon. Every lap helps us to learn a lot, but unfortunately not as much running as I'd have liked today."
Rosberg also denied he was concerned about the apparent lack of pace with the MGP-02. "It's a steep learning curve," he said. "There is a lot of hard work ahead, but with the developments that we have to come, I am confident that we will continue to progress."
Continuing the trend it has set for the majority of winter testing so far, Red Bull ended the day in with eighth fastest, courtesy of a 1m22.222s lap from defending world champion Sebastian Vettel. Set in the first half of the day, the German then concentrated on heavy fuel load runs, lapping within the 1m25s and 1m26s region.
Concern is apparently brewing at McLaren after Jenson Button, working mainly on long stints, declared himself unhappy with the car's balance on his way to ninth place and a fastest time of 1m22.278.
McLaren issued a statement in light off the 2009 world champion electing not to give an immediate quote to the press: "A frustrating day of running," it read. "With windy conditions compromising our data gathering programme and affecting efforts to find a satisfactory set-up for the MP4-26.
"Jenson was unable to find a suitable balance with the car, and the team's progress was brought to an early end in the middle of the afternoon following the failure of an internal component."
Jerome D'Ambrosio endured a frustrating day for Marussia Virgin after a four hour delay caused the team to abandon much of their intended programme. The Belgian completed a mere 45 laps and the second slowest time of the day on a 1m22.985s.
Despite propping up the field on a 1m23.111s, Force India's Paul di Resta declared himself happy with the team's progress, despite spinning off at the Dry Sack hairpin with just under half an hour of the day to go.
"Another productive day with a lot more miles on the car," the Scot confirmed. "At the moment that's what it's all about - giving ourselves a clear direction and getting as much data as we can on the performance of the new car on different fuel loads. We're not going for times, rather fine- tuning the balance and set-up, plus getting to grips with a few development items we will use at the next test, including the DRS [drag reduction system."
As expected, the heavy clouds appeared with fifteen minutes to go and the subsequent sprinkle of rain was enough to entice Buemi, Alonso, Rosberg and Barrichello onto the circuit and gave each the chance to sample the Pirelli intermediate tyres.
The winter testing now moves on to Barcelona this coming Friday.