Jenson Button in the McLaren MP4-29 Mercedes.  (Photo: Glenn Dunbar/LAT Photographic)

in the MP4-29 .
(Photo: Glenn Dunbar/LAT Photographic)

Jenson Button topped the times in today as the McLaren MP4-29 made an impressive debut after failing to get on track yesterday.

Most of the teams have begun to log some proper mileage, but it was a troubled day for all three Renault runners as and did very few laps, and Toro Rosso spent all day in the garage.

The first few hours were run in damp conditions after Pirelli opted to use it for wet running. The track was artificially soaked before the action started, and for a while there were light showers. Later the sun came out and teams switched to dry tires.

Button ran a total 43 laps, which was a good effort for the car’s rollout.

“It’s always a weird one, sat in your motorhome all day long hoping that they build your car,” he said of yesterday’s wait. “We had a lot of issues yesterday, nice to see that we’ve been able to solve them overnight. Lots of start-ups I could hear from my motorhome, so I wasn’t worried about being woken – it was nice to hear that the engine was starting! Not a lot of laps today, 43, but I think a positive start.”

Kimi Raikkonen completed 47 laps for , and technical director James Allison said he was happy with progress thus far.

Valtteri Bottas was third quickest as put in some proper laps after appearing late yesterday, while a revised front wing allowed Nico Rosberg to log an impressive 97 laps as the Mercedes W05 ran reliably.

Sergio Perez was fifth fastest for , although the Mexican stopped on track in the afternoon.

“Today was a lot more productive than yesterday so in that respect we are making progress as we learn about the car,” said Perez. “We still have a long way to go with understanding the complexity of all the systems so it’s important that the next two days with Nico and Daniel give us the information we need before we arrive in Bahrain. It will be only then that we can hopefully start to work on performance.”

’s Esteban Gutierrez had a spin into a gravel trap, and finished the day in sixth spot.

“Today we were able to do a lot of laps, which is very positive,” said Gutierrez. “Considering the circumstances, it is very important to put in this mileage. We found some issues in the systems, which is something to work on and part of the process. Obviously at this stage I was not able to push. Before we can take it to the limit our priority is reliability. We had some issues with the braking system, where it was better to go easy in the braking zones, figure out how the system reacts, get mileage and sort it out.”

Vettel did not do a representative lap time, his token 1m38s was over 14s off Button’s pace. In two days he completed just 11 laps before heading home, as Daniel Ricciardo takes over tomorrow.

“Obviously we’ve not had a lot of running and have a few problems to sort out,” said Vettel. “But with such big rule changes it is usual to have some teething problems. That’s what tests are for, to sort those issues out. The next two days will be important to get some track time to prepare for the tests in Bahrain.”

Day Two Field And Fastest Lap

1 Jenson Button – McLaren 1:24.165 43
2 Kimi Räikkönen – Ferrari 1:24.812 47
3 Valtteri Bottas – Williams 1:25.344 35
4 Nico Rosberg – Merecdes 1:25.588 97
5 Sergio Perez – Force India 1:28.376 37
6 Esteban Gutierrez – Sauber 1:33.720 53
7 Marcus Ericsson – Caterham 1:37.975 11
8 – Red Bull 1:38.320 8