Driver: Valtteri Bottas
Chassis / Engine: FW37-01 / PU106B Hybrid
Location: Jerez de la Frontera 4.428km
Objectives: New component, systems and reliability checks
Weather: Dry and sunny
Air & track temps: 7 - 14ºC / 9 - 20ºC

The opening day of testing at the Jerez circuit for the Williams Martini team would see the team start the day by first unveiling their 2015 challenger the FW37. Present were Valtteri Bottas, Felipe Massa, Suzie Wolff and newly signed Alex Lynn. Carrying out the driving duties for the team on the first day would be Valtteri Bottas. With the start of the morning session there would be a delay prior to the FW37 taking to the track with the team finishing some work in the garage adding parts to the car that had arrived late.

As the other teams started their test programmes it would be Ricciardo who would set the first time, 1m:29.141, not that times on the first day had any real meaning. The fastest time from the test in 2014 was a 1m:23.276. Rosberg would take to the track in the new Mercedes setting a 1m:25.057 with further improvement seeing him drop down to a 1m:23.986 and then a 1m:23.653. Vettel was now second in his Ferrari followed by Sauber's Ericsson and Ricciardo.

We still had yet to see Valtteri take to the track in his Williams. The McLaren Honda being driven by Alonso and the Torro Rosso with Sainz behind the wheel had yet to come out. Rosberg would lower his time with a 1m:23.325 seeing him close to the quickest 2014 time, running on the medium tyre. With one hour of testing the FW37 had yet to leave the Williams pit. Rosberg would continue to make improvements setting a 1m:23.106 with Ricciardo second, running on the hard tyre, followed by Vettel and Sainz. With nearly three hours of the session completed Valtteri would take to the track and complete a single installation lap coming back in to complete system checks. Valtteri would stay in the car as the team prepared it for another run. With well over half an hour in his pit Valtteri would finally return to the track. Valtteri's first time would be a 1m:28.479, seeing him sixth.

The quickest time was now a 1m:23.106 again set by Rosberg. Valtteri would pit after his single timed lap. Valtteri would return to the track and would improve on his earlier time finishing with a 1m:25.167 to be fourth. Valtteri would pit but would reappear shortly after and would close the gap to Rosberg with a time of 1m:23.906. Vettel was now third with a 1m:24.000. Valtteri would continue to put in laps running in the 1m:25s. Having completed a total of nineteen laps Valtteri would again pit while Rosberg would complete one hundred laps. Out on the track we would see Vettel move to the top of the times with a 1m:22.958. This would see both Rosberg and Vettel having set times quicker than those set in the 2014 test.

Valtteri would return to the track and would complete thirty laps while on a longer run. Ricciardo would move ahead of Valtteri with a 1m:23.338, seeing Valtteri now fourth. Valtteri would complete seven laps prior to pitting again. After a short stop Valtteri would return to the action with just over two hours remaining. Valtteri would set times in the 1m:26s as he continued his next run having completed forty laps
at this point. As the final hour approached Valtteri would have completed fifty one laps. Having done very little running in the morning it was a god turn around for the Williams team. At the front Vettel would lower his quickest time with a 1m:22.690.

Valtteri would return to the track lapping in the 1m:25s as he completed sixty laps with just over thirty minutes remaining. Valtteri would complete the day gaving done seventy three laps.

Rod Nelson, Chief Test and Support Engineer: We have gone through our normal winter test programmes today and have solved any issues that have arisen. We lost a bit of time this morning but once on track, Valtteri clocked up 73 laps. We have new hardware on the car and there is a new power unit, and all of these have to be checked and tested whilst we are running before we can start looking at performance. Jerez isn’t too representative as a circuit as the surface is so abrasive, this limits the amount of useful performance work we can carry out. We are very satisfied with the first day and are looking forward to tomorrow.

Valtteri Bottas: The day started off a bit slow, but it ended turned out to be a really good one. After that initial set-back we didn’t have a single issue with the FW37, which is impressive for the first day with a new car. We started off on shorter runs before longer runs later this afternoon, including one run that was significant considering again that it’s only the first day. The car was consistent, so it’s a really good start to the week and we are pleased that it’s still a step up from the car we had at the end of last season. We know we have a lot to learn and improve, but we also know where these gains can come from, and have work to do with the car performance and the power unit. There are a lot of strengths in this car and we’ve made good progress in just one day, so I am very pleased.

Driver 		Team 		 Best Time 	Best / 
						Total Laps
1. S. Vettel 	Ferrari 	 1:22.620 	45 / 60
2. M. Ericsson 	Sauber 		 1.22.777 	52 / 73
3. N. Rosberg 	Mercedes 	 1:23.106 	11 / 157
4. D. Ricciardo Red Bull 	 1:23.338 	26 / 35
5. V. Bottas 	WILLIAMS MARTINI 1:23.906 	11 / 73
6. C. Sainz 	Toro Rosso 	 1:25.327 	24 / 46
7. F. Alonso 	McLaren 	 1:40.738 	5 / 6