Felipe Massa fastest as testing resumes in Barcelona
Brazilian Felipe Massa completed two and a half race distances and put his Williams team on top of the timesheets as Formula One's final pre-season test got underway in Barcelona on Tuesday.
"I don't remember before doing a day with 168 laps in my career," said the 35-year-old Massa, whose fastest was one minute 19.726 seconds.
"It was a lot of laps and I can feel it a bit on my body, but I am good. I feel in good shape for the new season," he added.
Triple world champion Lewis Hamilton, the bookmakers' favourite for a fourth title this year, was fourth fastest with a total of 49 laps. Bottas, who took over the car in the afternoon, did 86 and was fifth.
"I think Ferrari are possibly the favourites," said Hamilton, whose running was cut short after the champions discovered damage to the floor of the car.
"We can't take our eyes off them because they have been doing such a great job at the moment.
"Red Bull look like they have gone quite quick today as well. We'll see over the next days and, most importantly, over the next weeks, but it's going to be close in the first race, that's for sure."
The season starts in Australia on March 26. Ferrari failed to win a race last season, when they finished third overall, and have not been constructors' champions since 2008.
McLaren's woes continued, with an electrical issue on the power unit of Belgian rookie Stoffel Vandoorne's car forcing Honda to replace it, costing the team more track time after a difficult first week.
"Based on this testing we can expect to have a few engine changes, but they (Honda) will have addressed this before the start of the season or at least quickly into the season," said McLaren Racing Director Eric Boullier.
Vandoorne completed 80 laps but was more than two seconds off the pace.
Renault's Jolyon Palmer managed only 15 laps due to a power unit problem but he handed over to team mate Nico Hulkenberg who completed 58 in the afternoon. (Reporting by Alan Baldwin in London, editing by.Ed Osmond)