Driver: Valtteri Bottas
Chassis / Engine: FW37-01 / PU106B Hybrid
Location: Circuit de Barcelona-Catalunya, 4.655km
Objectives: Performance and Aero work
Weather: Warm and Dry Air & track temps: 10 - 21ºC / 12 - 32ºC

The final day of pre-season testing for the Williams Martini team would see Valtteri Bottas returning. Valtteri would complete several installation laps prior to pitting. He had gone out on hard tyres on what was a chilly morning. Perez was having his first run in the 2015 Force India and with twenty minutes of the session run it would be Rosberg quickest with a 1m:25.678, followed by Perez and Vettel. Valtteri had yet to set a time as Rosberg went quicker with a 1m:25.492. Forty minutes into the session and Valtteri would return to the track while Rosberg would pit after an eleven lap run. Nasr was now second followed by Perez and Vettel. Rosberg would come back out and continue to put in the laps. His first time was a 1m:25.496 just off his previous mark. But his next lap would see a 1m:25.277 improving his fastest time while running on the medium tyre.

Rosberg would pit after a ten lap stint lapping in the 1m:26s. After the first hour Valtteri had completed sixteen laps. Valtteri was still in his pit as Rosberg returned to the track and would lower his quickest time with a 1m:25.186. But the session would be red flagged when Ricciardo stopped at the end of the pit lane. The Red Bull was pushed back to the pit lane and the session restarted. With two hours run Valtteri wa third with a time of 1m:26.440. Rosberg was still fastest with Verstappen second with Valtteri having completed twenty two laps. Valtteri would return to the track this time on the unmarked mediums and would set a new quickest time with a 1m:25.009. Valtteri would pit but after a short stop would return with a set of soft tyres and would set a 1m:23.859. But his next run would see him use the super soft tyre and would set a 1m:23.063 in what was a qualifying simulation. This would be two tenths faster that Felipe had set yesterday Valtteri had now complete thirty four laps

Roughly thirty minutes later Valtteri would do a hard tyre run while other drivers were on softer tyres seeing Vettel move into second with a 1m:23.469 also on the super soft tyre, followed by Nasr and Perez. McLaren had only been able to do two laps as they were restricted in their running by a sensor issue. The lunch break would see running come to an end with Valtteri still quickest. With the start of the afternoon session it would be red flagged not long after it started with Maldonado crashing his Lotus at Turn four in what was a big accident. The car would be cleared and the session would get underway with just over three and a half hours remaining in pre-season testing. McLaren would finally see Button set a lap time with a 1m:28.782 followed by a 1m:28.391. Button would continue to find pace setting a 1m:26.832 prior to pitting.

Another red flag this time from Verstappen who had stopped his Torro Rosso out on the track. His car would be recovered and the green flag would be shown. Button would set a new personal best with a 1m:26.323 running on the soft tyre. Nasr would complete one hundred laps with Valtteri sixty three. Ricciardo would come out on the soft tyre and would post a 1m:24.638. Button was back out and would set a 1m:25.994, but this was 0.7 behind Magnussen's time on Saturday. Rosberg would also complete a hundred laps while Perez was up to eighty eight. Vettel was out on a race simulation while behind the scenes teams started to pack up their gear. Valtteri was back out on the track but would pit.

Two hours remaining in the session and the Williams team would announce that they had completed their winter testing and that their next stop was the Australian Grand Prix. Valtteri was currently quickest having completed eight nine laps. Button was back out for McLaren and would complete a supersoft run setting a 1m:25.327. Vettel was on a race simulation with an hour remaining.

Rod Nelson, Chief Test & Support Engineer: Today’s programme was similar to yesterday, as we try to get the drivers in the best position before heading to Australia. Due to this the focus was more on performance with a mixture of long and short runs rather than just reliability work. Both drivers have worked extremely hard throughout the test and the entire team have worked very well together. We are really looking forward to Melbourne.

Valtteri Bottas: It was a really good day and a great way to finish the test. One of the main points we have learnt is that the FW37 is very reliable. The car we are taking to Melbourne is very competitive and should make for an interesting start to the season. We have made the most out of our time testing and I need to say a really big thanks to the team, not only trackside but also everyone back at the factory as they have produced a really quick and reliable car.

WILLIAMS MARTINI RACING will be back on track for the first Grand Prix of the season in Melbourne, Australia.

Driver 		  Team 	    	   Best Time 	Best / 
		   				Total Laps
1. V. Bottas 	  WILLIAMS MARTINI 1:23.063	33 / 89
2. S. Vettel	  Ferrari	   1:23.469	48 / 129
3. F. Nasr	  Sauber	   1:24.023	64 / 159
4. D. Ricciardo	  Red Bull	   1:24.638	81 / 85
5. S. Perez	  Force India	   1:25.113	21 / 72
6. N. Rosberg	  Mercedes	   1:25.186	46 / 130
7. J. Button	  McLaren	   1:25.327	24 / 148
8. M. Verstappen  Toro Rosso	   1:25.710	28 / 30
9. P. Maldonado	  Lotus		   1:28.272	22 / 36