Driver: Felipe Massa / Valtteri Bottas
Chassis / Engine: FW37-02 / PU106B Hybrid
Location: Circuit de Barcelona-Catalunya, 4.655km
Objectives: Pitstop practice
Weather: Cold with a few showers Air & track temps: 4 - 14ºC / 10 - 18 ºC

Day three of the Williams Martini teams Barcelona test would see both Felipe Massa and Valtteri Bottas share the driving duties. Williams had modified its original testing plan with pitstop practice today been the focus, with Felipe doing the morning then Valtteri running in the afternoon. Felipe would take to the track early even though the session would be halted with a red flag when the Ferrari of Vettel spun into the gravel. The session would re-start with Felipe back out. His run would be short coming back in without setting a time. Upon his return to the track Felipe's first timed lap would be a 1m:27.544 to move into second behind Hamilton. He was running on the medium tyre as he continued to put in further laps in the mid 1m:27s.

With an hour run Felipe had completed nine laps as he continued to circulate around the track. Felipe would improve with a 1m:26.912 to close the gap to Hamilton. Another red flag as Button stopped out on the track at Turn seven. With the track green again Felipe return to the track but would come back in again for a practice pitstop returning to the track. He would again pit having completed twenty six laps. After a short stop Felipe was back out running on the development hard Pirelli tyre. Again Felipe would pit and again he would complete a pitstop, returning to the track only to pit again shortly after. The times now saw Verstappen fastest with a 1m:24.739 followed by Hamilton, Vettel, Kvyat, and Felipe now fifth. He had now completed thirty nine laps with three hours of the session completed.

Felipe would return but was back in soon after as the team continued their pitstop practice. But there were now reports of rain seeing Felipe pit with forty five laps behind him. Thirty minutes later and Felipe would return to the track this time running on intermediates. It was a very disjointed run from Felipe with his runs been broken by returns to the pit lane. Felipe would pit for the lunch time break.

The afternoon would see Valtteri take over with his running focusing on pitstops seeing him complete six laps without setting a time. He would continue the process of pitting returning to the track only to pit again. Of the other drivers Maldonado would be quickest with a 1m:24.348 followed by Verstappen, Hamilton, Vettel, Kvyat, and Felipe. With two hours remaining Valtteri had completed twenty two laps without setting a time. It was certainly making it hard to judge the pace of the FW37. Thirty laps from Valtteri with an hour remaining in the day.

Valtteri would return to his garage and it would not be until a red flag caused by Verstappen was cleared that he would again return. He would finally set a lap time after his long run of pitstop practice. He would set a 1m:38.067 but his next lap would see a1m:27.556.A few more laps but he would not improve on his time as the session came to a close. Valtteri would complete forty nine laps close to the fifty five of Felipe.

Rod Nelson, Chief Test & Support Engineer: We were expecting rain today so we changed the plan slightly. The day was dedicated to pitstop practice and we ran through various scenarios, issues and problems we may encounter in a race situation. I am happy with the way the team has managed themselves and worked with the issues thrown at them. We have a busy programme planned for Valtteri tomorrow so hopefully the conditions are good.

Felipe Massa: I did a few laps at the start of the day, but it was hard to gain anything from my perspective. The programme for the day was to practice the pitstop procedure which come a Grand Prix are always important. It is positive to have the team ready and it’s always good for the driver to practice so the team know what to expect. The whole procedure has to be quick and we can only do that by practicing.

Valtteri Bottas: The programme for the whole day was pitstop practice. It was difficult to get a feel for the car on the rest of the lap as I was on old tyres and my only proper run was when the track was very cold at the end of the day. It was good for the team to practice the pitstop procedure, but also for me to practice too. Australia is just a few weeks away and we need to be ready for all elements of the race. Every stop is important and it’s good to be well prepared.

Driver 		   Team 	    Best Time 	Best / 
		   				Total Laps
1. P. Maldonado	   Lotus	    1:24.348	57 / 104
2. M. Verstappen   Toro Rosso	    1:24.739	53 / 129
3. L. Hamilton	   Mercedes	    1:26.076	63 / 101
4. M. Ericsson	   Sauber	    1:26.340	43 / 53
5. S. Vettel	   Ferrari	    1:26.407	23 / 105
6. D. Kvyat	   Red Bull	    1:26.589	28 / 112
7. F. Massa	   WILLIAMS MARTINI 1:26.912  	11 / 55
8. P. Wehrlein	   Force India	    1:27.333	47 / 81
9. V. Bottas	   WILLIAMS MARTINI 1:27.556	45 / 49
10. J. Button	   McLaren	    1:29.151	4 / 24